It's kinda funny how GameCube emulation is still notoriously poor (remember how badly even the official Switch port of Mario Sunshine ran?) but every Nintendo console since then lends itself so well to emulation. And that's even accounting for the Wii and (3)DS's hardware gimmicks!
Not to pile on, but to agree with the sibling comment: Dolphin (the GameCube and Wii emulator) is insanely good. It seems like Sunshine has weird issues but I've never had a negative experience with anything else and it works out of the box everywhere, even on Linux.
As a tangent just because of how impressed I was, I installed Dolphin on Linux via a Apt (I believe) and it just worked. I already had the GameCube USB adapter drivers installed and those just worked out of the box. I don't know how drivers work for selectively compiling with them from the kernel tree, but it appeared that they were part of the main kernel tree and they were just there for me.
I don't understand what you're talking about. GameCube emulation is excellent. You can use the same emulator responsible for Wii, Dolphin, and it has great compatibility.
Aren't GameCube games prone to weird issues and artefacts though?
For example, most emulated versions of Mario Sunshine (including the official Switch release!) show these little grey debug cubes in certain levels: https://tcrf.net/Super_Mario_Sunshine#Debug_Cubes
Mario Sunshine is a game where doing anything beyond the original (Running at high resolution, Widescreen mode, 60FPS mode) will break the game. I wouldn't blame Dolphin for bugs that only show up when you exceed the capabilities of the base hardware.
The ugly spot is the 2000s, but the ps3 and 360 emulator are quickly improving.
Wii/DS/3DS/Switch emulation is basically perfect.