Wayland is a modular communication protocol that specifies how a compositor interacts with its clients, as well as a replacement for X11.
Wayland does not aim to provide a commonly used compositor implementation that could be used by everyone.

This modular approach allows for different desktop environments to have their own Wayland compositor implementations that reliability produce the same or virtually the same output based on the communication specifications without the increased challenges of integrating it into existing Desktop Environments or Windows Manager as it allows for more flexibility in implementation. As an analogy, it’s like if several people were making the same type of sandwich in different ways, as long as the “client” (the application) gets the sandwich they asked for, the specific process doesn’t matter.

In contrast, Xorg is a single, monolithic X11 implementation. Due to Xorg’s dated, non-modular design, maintaining and extending it’s functionality is extremely difficult. Infact, it’s lack HDR support to this day is due to its inflexible architecture.

Wayland compositors combine the functionality of a display server, window manager, and compositor into a single component. This simplified architecture is one of the main design goals of Wayland compared to Xorg/X11 where the compositor & window manager are separate components. This approach ultimately streamlines the rendering pipeline where applications render locally and communicate directly with the compositor, cutting out the X server entirely. Wayland’s client-side rendering is more modern and cleaner than Xorg’s approach.