Afaict wine uses XWayland. Sometimes with my games I'll have problems like the game running on one display and expecting input from the other, even when I've switched the second display off with wlr-randr. I also have occasional UI scaling problems. Most things works well most of the time though.

With a good compositor, Wayland itself is probably ready enough for most cases. A lot of applications need to be updated to better support it though., and that seems like a lot of work.