Why should the applications get to decide if they are appropriate for a particular age? Shouldn't that be up to the parent? I shouldn't need to tell my kid: "Well, to use this compiler software, you need to set your age to 18 temporarily, because some product manager 3,000 miles away decided to rate it 18+. But, set it back to age 13 afterwards because you shouldn't be on adult sites." It's stupid.

I get what you mean, but I might have miscommunicated a bit.

Clarification: "are set to" means by the parent. "Accounts and Applications to services that provide countent" like media content providing apps like discord, netflix, etc. that ARE able and/or bound to rate their content.

Package Manager and Software Installation in general are usually locked behind root/admin passwords anyway. Especially on kids' devices their user should be non-admin, no?

So, when any piece of software is installed, it is by choice of the parent.

That's not unreasonable then?

That is what I meant by age(-rating), you are correct. However, drop country specifics - too complicated. Age brackets are enough: child, preteen, teen, adult. At around 16-17 these should be dropped anyway since at that point people are smart enough to get around these measures anyway and usually have non-parent controlled devices.