Wii U was so far ahead its time that most people, including this community, only just caught up to its greatness.
Everything about it was pure gen 1 research concept bought to retail but there were flashes of genius strewn throughout and it could've evolved into something very special that the entire industry would've mimicked as per usual. Something as simple as calling it Wii HD and bringing it to market a year earlier could've flipped the script. The Switch in comparison is a watered down, anemic version of the Wii U and, guess what, people ate it up.
Go and play Deus Ex: Human Revolution with the gamepad and tell me that all immersive sims don't need that feature. Kirby is another one. ZombiU and the inventory which can be extended to all RPGs etc.. like Tokyo Mirage. Rayman is the definitive version due to the tablet as would've Zelda been. Mario Maker. Lego City. Captain Toad. Wonderful 101.
List goes on...
Much like the jump from 2D to 3D had developers trying to catch up before they could innovate thats what the Wii U was and from what was seen above it could've evolved into something amazing. Like a second gen refresh in which the tablet looked like a Switch and could be taken out of the house for portable gaming as well as being used as a controller or taken to someone elses place to "visit" their Animal Crossing town etc.. like a pimped out Street Pass
Instead it flopped so they dumbed it down, ported across the games after nerfing their best features and released a device with atrocious build quality and dubious durability. Only to make millions.
No wonder Nintendo hates gamers.