Article showing performance differences between Wayland with power efficiency, Wayland with color accuracy and X11 desktop sessions in Plasma 6.4 on a generic laptop with integrated AMD graphics, superior X11 results across the board, various new Wayland bugs and problems, fundamental philosophical ...
So, it uses marginally more resources, can't take a screenshot of a cursor, and you have to move your windows to where you want them yourself when you restore session. Plus, if you want to learn how to make a keylogger, it's much simpler with x11.