Then how do you explain the continued success of Mint?
Because Mint’s philosophy is to make a friendly, simple and usable system for everyone.
That may be for people who came from Windows before, or those who like their OS to be a bit more conservative, meaning no flashy stuff, boring, and just working. Just like Windows was “in the good ol’ days”.
This makes it accessible and usable by everyone, including Linux sysadmins who come home after work and don’t want to deal with annoying computers and fixing things.
Everything on Mint feels high quality, functional and cohesive.
ElementaryOS on the other hand feels like a cheap MacOS clone, but nothing works. Those who want Mac, buy a Mac.
Mint/ Cinnamon on the other hand is similar to Windows (XP, 7, etc.), but not a copycat. It’s familiar enough to be intuitive for Windows users, but much enough it’s own thing.
Mint’s main focus is to get a uncomplicated, and usable system, while Elementary’s focus is to just do what Apple does. … Well, did. 15 years ago. They totally forgot how much work maintaining a distro and a desktop with a whole app suite is, and just stopped working on it.
While Gnome and KDE (and other WMs/ DEs) got magnitudes better in just one year (e.g. Plasma 6), Pantheon (and Elementary) just stagnated the last 5 years or so.
They don’t even offer/ work on Wayland yet, or other new things.
Either they’ll stop working on Elementary, and focus only on Pantheon, so it can live on on other distros, or it will just continue dying like it does currently.