What does it mean by removing X11 support?

> The part that talks to the hardware is called the client, and the part that talks to other software in order to render it/compose windows/etc. is called the server.

Are you sure? That's the opposite of the diagram in the Wikipedia article you linked to.

In 1980s-era X11, my understanding is that the client is the application, which might be xterm or xeyes or something, and does not talk to the hardware at all, only to the X server; and the X server talks to the hardware on behalf of all clients. The X server is a server in the sense that it calls listen() and accept() on a socket, and the X client application is a client in the sense that it calls connect() to that socket.

The way in which it is backwards is that if you're using remote X11 to run an application (perhaps something that does heavy number-crunching) on a large computer that you might call an application server, displaying its output on a lightweight terminal that you might call a thin client, then the X client (software) is running on the application server (hardware) and the X server (software) is running on the thin client (hardware).

In newer X11 applications and toolkits, increasingly both the client and the X server talk to the hardware, and the X server's role is more about coordination than rendering, but the connect()/listen() are still the same way round as they always were.

Wayland is also the same way round as X11: the client is the application, which calls connect(), and the server is the centralized thing linking all your applications together (in this case it's called the Wayland compositor), which calls listen().

Other infrastructure components like Pulseaudio, Pipewire and D-Bus are also the same way round as X11 and Wayland, with one centralized server that calls listen(), and lots of clients that connect() to it.