There's an entire competitive scene for this game, so you're not the only person still playing this game. It's probably the most active Mario Kart game besides 8, especially thanks to mods that allow for online play, combined with the ease of modding the Wii.
I still play Wii games, all the time! In fact, just yesterday I revisited Mario Party 8 with my siblings--say what you will about it but I have a ton of nostalgia for it and it's still a pretty darn great party game.
And yeah, while I prefer MK8 to MKWii, my sister prefers the latter and we still revisit it quite a bit as a result. And yeah, nostalgia applies here too. Just today I created a mod of the game that lets me use the Wii U GamePad, and it feels as smooth as ever.
Alongside the tournament I'm running, I've also been playing Donkey Kong Country Returns for the wiki. There's also a few games on the system I have yet to complete, like Metroid Prime 3 and Kirby's Epic Yarn. I mainly use my Wii U, however, as my brother has the Wii in his room.
I rarely play it as I tend to play GameCube, Wii U, or Switch more. I don't really like Mario Kart Wii all that much. I vastly prefer Double Dash!!. It's my favorite game in the series. It's worth playing Double Dash for the fun.
I play Super Paper Mario quite a bit, albeit not often on console anymore as opposed to Dolphin. My Wii itself is... not in good shape so any Wii games I do play on console are usually on the Wii U. But even that's getting rougher in shape so i don't use it as much...