Yes but this a problem, you get very fragmented systems, tons of wasted space and resources (because your CPU/RAM will pay as well) and even worse you create a situation where developing Linux desktop apps isn't just attractive to anyone.

Just to prove this point I'm sure you've noticed that the largest growth in Linux "desktop" apps (be it single developer apps or more "professional" stuff) was around the time Java desktop app became popular and then later on with Electron because at that point those packing solutions were dealing with the Linux DE mess (the constant updates and breaking of things) behind the scenes and the developers only had to add a very few checks into their code to handle all Linux systems.

What I'm saying is that by have all that DE choice and constant fuckery we're making our lives worse in the sense that nobody same wants to develop to such platform thus getting less software and making Linux less of an alternative. Until we don't get a single DE with a single solid and well designed theme, UI library, developer friendly frameworks and whatnot Linux won't be getting any meaningful traction among regular people and professional developers.

GNOME and their large backing was a way to fix this mess and make all other DEs fade away but then their purist vision and CSS themes got in the way of optimizing the DE for the mass market and take over everything as they should have had.

The DE that will take Linux to succeed in the desktop doesn’t need themes, customization and all the personalization that would make it really hard to create. Hell it don't need to be much, it can even be a simple 1:1 copy of the macOS desktop experience (and keep it updated) and it will likely become very popular in no time and send GNOME, KDE and others into oblivion.