X only exists because it pre-dates Linux and Open-Source in general. It was developed at Stanford and spread to MIT and became a de-facto standard in academic computer labs. It came from the need for a graphics stack. Wayland, conversely, is what you get when the Linux community tries to create their own thing from scratch. True to Conway's Law, it's a loose confederacy of mini-projects that are all equally "wayland". Just look at hyprland, which the community tried to eject, yet people still use it.