Both Google and Facebook were caught breaking the rules when it came to using internal certificates and were having users install privacy invasive apps.
While you're not wrong, I think it's a fallacy to say that just because people break the rules doesn't mean we should not make rules. Lots of people get speeding tickets, that doesn't mean we should abolish speed limits.
Companies break rules, they get caught, the rules get changed and improved and hopefully things tend to get better (in theory).
I agree with making rules. But since developers as a whole can’t be trusted and there are technical ways that Apple can enforce to ensure that the rules aren’t broken (in most cases), I think they should.
https://techcrunch.com/2019/02/01/facebook-google-scandal/
Not to mention FB buying a VPN provider specifically to spy on users.
So if Apple can’t trust two of the largest tech companies in the world to follow the rules, are they suppose to trust Joe Random Developer?