The Wii U is a highly underrated machine, as I've stated many times in the past. The Nintendo Switch is also a great machine. I have both and I love both very much. However, I think I like the Wii U more. There are a few reasons for this, and I'll go over that here.
The Controller
The Wii U and the Nintendo Switch have comparable control schemes in 3 ways- with a big screen in front of you via the GamePad or Switch handheld mode, with a regular controller via the Wii U Pro Controller or Switch Pro Controller, and with 2 controllers via Wii Remote & Nunchuk or the Joycons. Each control scheme has its fans, but I think the Wii U has better control schemes than the Switch.
If you want a big old screen in front of you, Wii U is absolutely the way to go. The GamePad is soft in the hands and bulky enough for you to get a good grip. It doesn't feel heavy, but you can tell it has a lot of features. One thing the Wii U Gamepad does right that the Switch handheld does wrong is, the charging port is on the top of the GamePad. I understand why the Switch has the port on the bottom. However, playing while charging is much easier with the GamePad. The GamePad has a stylus as well. The Switch has a capacitive screen as opposed to a resistive screen, but I don't really mind the Wii U screen. It works really well and it seems more durable.
If you want to use a regular controller, this is where it becomes a close call. The Wii U Pro Controller and the Switch Pro Controller are both very good controllers. However, I like the Wii U controller just a bit more. The Wii U Pro Controller is what the Xbox 360 controller should have been- it has a great form factor and it fits into my hands great. The soft, yet responsive buttons are very comfortable, and the triggers feel very comfortable to hold down whereas the 360 triggers get to be painful. The Switch Pro Controller is closer in feel to the Xbox One controller. While the Xbox One controller is much better than the Xbox 360 controller, so is the Wii U Pro Controller. The controller itself is very comfortable, but it's not without its flaws. The triggers are slightly stiffer, but it's barely noticeable. The D pad on the Switch Pro Controller is not as good as it is on the Wii U Pro Controller. Pressing the center buttons on the Wii U Pro Controller is easy because of the position of the thumbsticks. However on the Switch Pro Controller, pressing the Home button becomes more difficult because the right stick is in the way. Overall both are great controllers, but the Wii U Pro Controller feels better to use.
If you're using separate controllers, it's no contest. My Joy Cons have stick drift. Need I say more? The Wii Remote and Nunchuk have the disadvantage of being tethered together by a cable, and the Joy Cons provide much more freedom with their separation. However, there are disadvantages that come along with this. Like I said earlier, the Joy Cons get stick drift eventually. The motion controls aren't as accurate, because Joy Cons use gyroscopes instead of infrared pointers. So while the sensor bar is cut out of the equation, it doesn't work as well. It's not terrible, but in a lot of games the Wii Remote Plus is better.
Online
I don't play too many online games, but I play a few. I've put a lot of online hours into 2 games- Splatoon on Wii U, and Mario Kart 8 on Switch. I think it's fair to assume that I've put a near equal amount of time into the online gameplay of both of these games. Back in my Mario Kart 8 online days, network errors were common. At least once an hour, I would get booted out of the lobby and I'd have to rejoin. Sometimes it didn't let me join again for some time. In Splatoon on Wii U, this is rarely a problem. I have been disconnected maybe 2 or 3 times in my time playing the game. I've never been disconnected from an online game in Super Smash Bros, and Super Mario Maker has never given me trouble. So what happened to Switch Online that made it so much more faulty? I can't tell for sure what the problem is. I know that there's a problem though. You guys should play Splatoon.
Friends
The Switch friend system can maybe be considered robust, but it dropped the ball in 2 very important areas. The Wii U does one of these correctly, and the other one is okay even though it also didn't do a great job.
Nintendo Switch, just like the 3DS, uses friend codes to add buddies to your buddy list. Why? Everyone knows how bogus this is. Why can't everyone just have a username, like every other platform that exists? Why do we need these pointless codes? Remembering "Storm9CP" is much easier than remembering whatever my friend code is.
Nintendo Switch Online voice chat is a mess. To chat online in many first party games, you must have their dedicated cell phone app. The Wii U doesn't need this app! Voice Chat on Wii U and Switch could stand to be improved. The Wii U needs an overhaul in this regard too, I'll admit. Voice chat should be based on the Wii U system, not the game. This is the system that Xbox Live uses. That way everyone can play different games and still be in the party. They could be doing whatever they want on the unit while this happens. As it is, voice chat is based on the game, so all people must be playing the same game. The Switch also needs a voice chat overhaul. They can make it part of their online service, but voice chat should be part of the system. A cell phone app shouldn't be required to run voice chat. My cell phone cannot install any apps, so I can't even use this service that would otherwise be available. Another thing that Switch needs to work on is Bluetooth headset support for docked mode. Sitting really close to the TV is not comfortable, and Bluetooth adapters aren't something I've ever seen at my local big box store. This solution would solve the problem that the smartphone app solves, but in a more graceful and convenient way.
Nintendo eShop
The Nintendo eShop has been a great place to find some of the lesser known games for the Wii U and Nintendo Switch. However, one of these stands above the others.
The Wii U eShop is clean, neat, and well-organized. Everything is categorized and easy to find. The homepage is well designed too. The music is dope too. The homepage does a great job of showcasing the wide variety of stuff available on Wii U. Navigation is easy, and discovery is easy.
The Nintendo Switch eShop needs a revamp. Everything is very loosely categorized, and discovery is difficult. It looks very bland and uninteresting. Discovery is very difficult as well. There's just too much stuff on the Switch eShop, and finding games of quality is very hard in the eShop's current state. Things need to be categorized better so it's easier to sort out exactly what you want.
Other online features
Some of this is Nintendo's fault, and some of it isn't. Either way, the Wii U has better online features than the Nintendo Switch. The Wii U has a web browser available from the home screen. It works pretty decently too, even though it may be a bit outdated. Switch just doesn't have a web browser, or at least not one that's reasonably easy to access.
Nintendo Switch has a strange lack of media streaming software available for it. Switch has Crunchyroll, Hulu, and YouTube. This is nothing compared to Wii U. While it no longer has access to Hulu (stupid Disney), Wii U still has access to Netflix, Amazon Prime Video, Crunchyroll, Youtube, and even Napster. That's a better selection than Switch, I'd argue.
I think now would be a good time to mention Miiverse and all the other online features that have been discontinued. There's no need to go in depth here because they are not around anymore, but Miiverse was awesome while it was still around. We also have Wii U Chat (a Skype-like calling platform), and Nintendo TVii (a live TV service).
Virtual Console
I'm not going to say the Wii U has the best Virtual Console out of all Virtual Consoles. That honor would go to the Wii. I can say Wii U Virtual Console is better than Virtual Console on Nintendo Switch, though.
For some, the Switch Virtual Console is quite a good deal. Pay 20 dollars a year for a few NES and SNES games. This includes save states and online play for multiplayer. I don't like this deal though. As users have pointed out, online multiplayer for these games doesn't work well. Why is it limited to NES and SNES games? Wii U had Virtual Console games for NES, SNES, Nintendo 64, Wii, Game Boy Advance, Nintendo DS, and TurboGrafx-16. No Master System, Genesis, or GameCube for some reason, but I think we had an alright selection as is on Wii U. Switch's Virtual Console library is severely lacking. Was anyone asking for Smash Tennis or Eliminator Boat Duel? Is there anyone excited to try out Eliminator Boat Duel? Wii U had save states as well, so save states are nothing special. The part I dislike most about Switch Virtual Console is that it's subscription-based. It may not be a lot of money for a subscription, but I'd rather just pay 10 bucks for Mario 64 and be done with it just like on Wii or Wii U. I hate having to pay for the same thing multiple times when I could just buy it once forever. The fact that these are only available through Switch Online is disgusting and ridiculous.
The User Interface
To some people, what the User Interface is like isn't important. As long as the games are good, then the games are good. But I like me a good UI. UI happens to be one of the biggest problems with the Xbox 360- the home page is filled with ads and garbage that could easily be removed. The Wii U has a great user interface, as I've discussed previously on this site. The Switch does not have a good user interface.
The Wii U's interface looks great. Once the home menu shows up and you're signed in, everything is neat and detailed. 20 boxes line the screen for each application. 3D models of the controller buttons float in the background. On the TV the Miiverse plaza is displayed. Everything is at a high resolution and it looks fantastic. When pressing the home button during a game, the same thing can be said- everything looks great. Everything you need during the game is organized along the bottom of the screen. The digital manual is readily available. Controller settings are easy to access.
The Nintendo Switch user interface looks awful. I don't understand our modern culture's shift towards minimalism. This has ruined many great things- the Patreon logo, the Google logo, the Cartoon Network logo.... a lot of logos. It's all so terribly boring. The Nintendo Switch is the epitome of bland. Everything is so squared off. Nothing has any gradients or borders; everything is a flat color. The Home menu, friends list, eShop, and settings all need a revamp, or at least some new themes. I understand that the menu was designed to work quickly, but couldn't it work quickly and look nice at the same time? All that can be said before bringing up how clunky it is. Only 12 games appear on the menu at a time, and you can only see 4 of them on screen before scrolling. Why can't I be shown 12 or 16 at a time? The 3DS could do it, so why can't the Switch?
Conclusion
I'm not going to argue that the games on either system are better or worse. That's not my call to make, because I'm not super well versed in Switch games since 2018. Based on just the consoles themselves, I stand by my opinion that the Wii U is much more fun and interesting than the Nintendo Switch. If you wanna fight, reach out to
@Icystorm9 on Twitter. Goodnight.