As a reminder, the topic is Wayland, and the great great great great grandparents post was referring to rendering/compositing systems DWM and Quartz as architectural equivalents to Wayland in the major closed source operating systems.

The parent, misunderstanding the discussion on compositors, diverted to a discussion about user interfaces. It's an understandable point of confusion given that Microsoft chose to name their compositor “Desktop Window Manager”, when the term “window manager” is typically scoped to user interface.