X11 is an ancient protocol originally developed for network use (with many graphical terminals connected to one server), it's mature in terms of features but ha

X11 is an ancient protocol originally developed for network use (with many graphical terminals connected to one server), it's mature in terms of features but has some inherent security issues. Apps can easily monitor your entire and there's no easy way to block that. It's also more prone to tearing. It was never intended to be frame-perfect in terms of timing. It supports network transparency which is great because you can start remote GUI programs over an SSH session. Wayland addresses some performance and security issues of X11 but still lacks some features. Apps need to be developed specifically for it (though dual stack is possible) which hinders adoption also. For example screen recording is often an issue. This is partly due to security but also because of it not being recognised as a major usecase from the start. Also, drivers are more of an issue with Wayland. Wayland doesn't have network transparency which I miss a lot. Personally I still use X11 :)