How would someone record GameCube Footage through something like Open Broadcast Software (OBS)? I'm pretty sure it's a capture card, but I'm wondering if there are other methods or is it the only way?

capture cards are the only way to record gamecube footage

Well, you could be a 2013 streamer and use your webcam Kappa

Yeah any capture card will do the trick. I personally recommend GV-USB2 for older consoles, it's only for composite cables though. If you use component cables at all, or anything with HDMI (such as a GC upscaler), then I use the Avermedia LGP, as it does both those things. (It just doesn't do composite though.)

Anything else, like webcam on TV, is not necessarily the best thing, and may be ruled out in the future. (IIRC, they did that with Super Mario 64, not this game yet.)

also hi son @xNose_

Yeah, my GC is using the original composites from when it was first bought. Ill probably check out the GV-USB2 then. Thanks.