It's not really something to figure out, it's just X protocol design was made for when thin clients running over the network was assumed to be the future, it wa

It's not really something to figure out, it's just X protocol design was made for when thin clients running over the network was assumed to be the future, it wasn't. Unfortunately though unlike Mac or Windows the migration to a better protocol has been ugly. When you start to consider things such as HDR, hardware planes (important if you want energy efficient video decoding) etc, the protocol just doesn't make that kind of thing easy, compared to Wayland which does by it's use of surfaces etc.