WiiU has a lot of great games you can play right now and it will take Switch few year before it reaches a similar level in it's life cycle. Also, it's the best console to play Wii games right now (and possibly ever) and there's plenty of games available from Nintendo's older consoles available on eShop. Considering that in few months it will be nearly impossible to buy a new WiiU I'd say it's the perfect moment to buy it.