As previously stated many wii u's are up for sale now because their owners are moving to Switch so prices are dropping a bit because of oversupply which is good for you.
wii u gets you;
1. A wide range of very low cost wii u software with some superb titles
2. A even wider range of wii software that now has fairly decent tv output to hdmi
3. With homebrew installed you can play gamecube games exactly as they should run (its not emulated) again with decent quality hdmi output
4. A range of homebrew emulators including a full speed DS emulator with upscaling that uses the gamepad as the lower screen and tv as the main screen
5. Homebrew wii and wii u games and apps which is quite an extensive list
Enough to keep you going for a long time. For me personally I'd much rather have a wii u than Switch at least for the next year. There is only a limited range of Switch software available for this year and for me only Zelda Breath of the wild (also on wii u) and Mario Odyssey stand out. So that's 1 game compared to 100s of fantastic games you can play on wii u.
As for the technical performance of the console comparison because the Switch is a portable its only made minor improvements on the wii u. Cpu is about 2x as fast, gpu is lower gflops in portable mode although more powerful overall because of later architecture and docked mode only provides a resolution boost.
The Switch is going to struggle to provide the big console experiences of older consoles like ps3 and 360. It's restrained by cartridge sizes and simply won't get that level of development support. Switch is a powerful portable but an appallingly weak home console.
Some people must have what's new, the latest thing and buy it despite the fact at the early part of its life its not worth buying due to minimal games available. Others maybe look at classic games they have missed because they didn't have that console in the past and now its available at low cost with very cheap games. Undoubtedly the second type of person gets a far better game experience and value for money.
It's a great time to buy a wii u.
Essay Pro