I love how I can just casually uninstall the entire desktop and install a new one in a few minutes.

genuinely curious since I’ve never tried or even considered it. What happens when you have multiple desktops installed, and assuming it doesn’t cause issues why would a person want to do that?

There’s no added value to having multiple desktop environments, so almost no one would want to. A lot of applications use DE sensitive configurations and there’s potential for conflicts as well as libraries incompatibility. Which can result on paradoxical and bizarre behavior from some graphical apps. It’s odd that it happens but it’s also not something devs plan or account for, so they aren’t even considered bugs. You don’t install multiple DEs at the same time unless you’re purposefully trying to break something or you don’t know better.

This is so wrong. Especially the assumption that almost no one would want to have more than 1 DE installed.

Most DEs have their own configuration which don’t conflict.

If the maintainer of a distribution has their shit together library incompatibility is no issue. Even on Gentoo you have to ignore everything portage is trying to tell you before you get in trouble.

In the past I even ran two DEs at the same time, sort of. You could start an xfce-panel while using enlightment.

Later I used Gnome and running my own fork of dwm in a nested Xserver. With wayland this option hasn’t gone thanks to Xwayland.

If systemd is correctly set up for it, you get a different seat for every DE, no matter if some seats are hosting the same DE or a different one. I am not sure what will happen if you have a graphical login with the same user, never tried it.