That's not the same thing. It's way easier to write an X11 window manager than to write a Wayland compositor, even with something like wlroots, because the window manager can speak the same protocol that clients speak, and it runs as a separate process.

As a concrete example, Emacs' EXWM package works by implementing an X11 client library in Emacs Lisp, then using it to talk to the X server (which is a separate process, so this works fine) and telling it how to position windows.

Whereas on Wayland, this is not possible without re-implementing a standalone compositor process, because otherwise architecturally it doesn't work. Emacs can't both do the drawing and be drawn.

No, that still requires you to make the whole thing, you just get help. For instance, I've run into a problem where I try some great new compositor that uses wlroots, and even though wlroots has good support for keyboard layouts I can't actually set the layout because the compositor hasn't wired up that functionality.

The article already addresses that...

It's not easy and the major compositors (Gnome, KDE) are NOT wlroots based, making this point mostly moot anyway.

This protocol at least has a chance of using a custom WM with an advanced compositor (which wlroots is not).

Especially with LLMs, the cost here is down significantly. People also drastically over-idealize what making an X window manager entailed: sure X had it's compositor, but you had to build so so much yourself.

I'm glad River is trying to create a bigger base here; this is way cool. And it sort of proves the value of Wayland: someone can just go do that. Someone can just make a generic compositor/display-server now, with their own new architecture and plugin system, and it'll just work with existing apps.

We were so locked in to such a narrow limited system, with it's own parallel abstraction layer to what the kernel now offers (that didn't exist when X was created). It's amazing that we have a chance for innovation and improvement now. The kernel as a stable base of the pyramid, wlroots/sway as a next layer up, and now River as a higher layer still for folks to experiment and create with. This could not be going better, and there's so much more freedom and possibility; this is such a great engine for iteration and improvement.