Considering Waylands history with lacking screen capture support and the amount of work that's gone into creating plugins like https://hg.sr.ht/~scoopta/wlrobs to support screen capture for wlroots based Wayland compositors this really doesn't looked like something OBS can or should fix. Until there's a standard way for applications to actually do screen capture similarly to X, Wayland is going to continue to be stuck as the 2nd choice for a lot (most) people.
Not to mention all the other things that don't work on Wayland, like VM key capture and Peek's event passthrough.