Is it just me or is every new distro just a base with a different DE? I started to notice this a few years back but not sure if it was my imagination or something developers starting doing because it was easier to ship the DE as "the OS" than it was to instruct users on how to switch to their DE.
Repositories and package versioning are also extremely important in ways newbies don't realize yet. There's a significant variety between using Debian, Ubuntu, Pop!_OS or Kali. They are all Debian based using apt but they are all decidedly entirely different systems with completely different purposes and uses.
My problem with Gnome is if it were my desktop, I might as well run Windows, since Gnome shell/mutter is slightly less capable than Windows. Extensions exist, but are very much a second class citizen and get broken by shell versions frequently, and the author of an extension may be gone when it comes time to rework it for a new version.
Plasma/kwin have pretty much everything I want in desktop/window management baked in.
I love gnome overall and it's my favorite de, but the missing features and extensions being almost mandatory for basic functions definitely are a pain.
Extensions are cool but the basics should be built in.
Nowadays fedora is a decent "boring" distribution, that finally settled into blatantly prompting to add the non free repositories you will probably want.
Ubuntu was annoying with it's little adventures in "not invented here" with mir, unity, and nowadays snap. So nice to have a modern, boring distribution.
Fedora also comes with a dozen different DEs prepackaged and installable with a single, simple command. Each user just can select and change their own desktop with a menu selection on the login screen
That's not usually the problem. Usually you can generally do this on any distro, even ones that have a higher level of integration with their DE.
The problem is more likely to be issues caused by overlapping configurations and base libraries that can cause weird issues if they aren't swapped out or kept default. If they aren't default and are managed by the package manager, usually the package manager will mark it as modified and often won't touch it unless you purge the configurations. Some will ask and some will straight up nuke em.
To me the problem is actually removing the old one. You can easily uninstall gnome, but it will leave behind config files and various data. It's less clean.
Also, there's an overlap in the libraries required by DEs, so you should use the "replace" option in you package manager (if it has one) to let o t figure out the best way to uninstall one and install the other.