I’m pretty sure this rule is only there to stop the hundreds of “flashlight” apps that used to exist. (Although, they appear to still exist) There isn’t tons of innovation or competition in “flashlight app” other than adding advertisements. There used to be a bunch of them that would only get popular out of necessity. The ones I’m seeing now in the App Store do seem to have non-default behaviors like “strobe light” at least, so they aren’t true clones of native functionality.
Apple isn’t using that rule to take down alternate weather apps, despite them having their own native weather app. There’s still plenty of QR code scanning apps, despite that being built into default camera app.
Flashlight apps were a 3rd party innovation. Apple didn't originally realize that the camera's light could be used that way. I wonder how many other useful features don't exist today because of Apple/Google's greed prevent a truly free smartphone market.
So what? Why not let there be flashlight apps if users find them useful? Apple doesn't have to recommend them in the app store and can sort them to the bottom of search results page. But why can't the exist. If people don't want them they will choose not to install them.
I'm fairly sure "Only high quality apps should be available to users" was said more than once when the Apple AppStore first launched (together with the second or third iPhone I think?). Apple isn't really into the whole "users can choose what's best" thing, which once you understand this, a lot of their choices become understandable (albeit shitty none the less).
And yet Apple has shown many times a willingness to use vague language of their rules to block apps they don't want. Past behavior can't predict future behavior.
Apple isn’t using that rule to take down alternate weather apps, despite them having their own native weather app. There’s still plenty of QR code scanning apps, despite that being built into default camera app.