I'm only on Linux for a few months (as a daily driver, always used headless servers before that), and I'm almost certain that my Fedora install came with both KDE and Gnome in Wayland and X11 flavors pre-installed out of the box, and I could just choose between them at login screen. Or am I wrong, and I do I just not remmeber installing the other manually? I mean, that's also possible, it's been a while.