It peaked at 4.05% in March. The last 2 months it went just below 4% as the Unknown category increased. For June the reverse happened, so 4.04% seems to be the real current share of Linux on Desktop as desktop clients were read properly/werent spoofed.
Mint is great and is absolutely enough for most people using computers, still as of now. It comes with its limitations though:
All of the above can easily be irrelevant to you and Mint is just perfect for what you need. It’s important to point out limitations of that choice, but crapping on it because you don’t like it is just pointless fuss
On your last point, there’s also Flatpak which is available right from the baked in software center… That’s not without its issues too, but they’ve been an overall smooth experience for me so far