Yeah, but a lot of people nowadays only use a phone, and they don’t download their software from a random website, but they use a front end (e.g. Play Store/App Store), so they don’t need to get accustomed to it

I agree, but only until the part you mention how people should install their software. And that’s simply because I don’t think that people should install random .exes or .debs from the internet, because repositories are:

1. Easier to find software within: you’ve got a one-stop-shop for all/most of your most important software
2. They’re inherently more secure as the software should (emphasis on should) be checked by maintainers or the people who upload software onto them
3. Software updates are much easier to enroll, as they are treated as system updates