The only problem with this approach is you have to be very rigorous with it. Accidentally log into the wrong desktop and that user is broken.
You also need to find a way to manage shared files. One way is to have all the users share the same UID but that will require you to create the users with a tool that lets you set the UID.
In the end, it is all doable but it still isn’t a “just works” type of scenario.
I forgot to say that I removed xfce after installing kde
I agree with this, I was very rigorous doing it.
I also had a common home folder that had all the download files, documents, pictures etc and had to symlink those folders every time I created a new user.
There were also some permission issues for some files/folder and I had to run scripts to change permissions.
Yup definitely isn’t just works and I had to learn a lot to set it up and manage it. This was my alternative to distrohopping.