Wayland was turned on by default in ubuntu 21.04 xorg (the x11 server) was removed from ubuntu in ubuntu 25.10.

Desktops like gnome have dropped support for x11 so you can expect that wayland will be the only way to do things from here on out.

There is a compatibility layer called "xwayland" that should work, but there's definitely some rough edges between x11 apps and wayland apps. x11 gave all apps a pretty large ability to intercept information from across the system. Wayland locks that down pretty significantly.