For sure and I agree that should be enough but the average person is not good with computers and they don’t want to learn. They won’t understand the nuances of different distributions of Linux. Like try explaining the difference between a .deb, a .tar.gz, and a .rpm to a person who’s already hésitent about using Linux. Flatpak solves that by just having one download that any Linux install can use
Ah, that’s actually what I was thinking of in my previous comment