I think the problem with btrfs is that it entered the spotlight way to early. With Wayland there was time to work on a lot of the kinks before everyone started seriously switching.
On btrfs a bunch of people switched blindly and then lost data. This caused many to have a bad impression of btrfs. These days it is significantly better but because there was so much fear there is less attention paid to it and it is less widely used.
I think you might be missing the part where wayland WAS running perfectly for them. It still does for me. I am actively and happily using Wayland and everything for me works. XWayland is a fantastic stopgap for now.
Wine is (slowly) getting a native Wayland port, which will translate to Proton eventually.