I use my Switch to exclusively play Smash Bros with my friends using GameCube controllers with the switch adapter.
My Switch has been having lots of issues lately though. Anyway to replicate that with the Steam Deck?
If you’re playing offline with friends, Emudeck has Ryujinx available. All you’d need is to either dump your cartridge if you can (which I don’t know how to do) or get a copy and make sure you got a dock to hook up your deck to the TV. I don’t know what kind of port the GameCube controllers use or if they’ll work, though. I don’t have one, so I couldn’t tell you. I know the 3rd party wired pro controller I have works fantastically, though. Only other thing you gotta worry about it having enough ports to plug in to depending on the number of players and dock you got.
As for whether the game will be as smooth on Ryujinx as it is on switch, that’s something I don’t know considering I’ve never tried it on my deck.
This reddit post leads me to believe that it is doable. I have the official Nintendo USB GameCube adapter and a Steam Deck, and I’d be happy to help you troubleshoot if needed :)
It seems like it should work great! 👍