If that's the case, why is Safari already worse than manifest v3, already hiding URLs, already promoting Apple News (more anticompetitive than AMP), and not even offering the ability to clear storage on exit?
Because Safari is a niche player. Anti competitive behavior matters a lot more when you have a stranglehold on a market than when you are just a bit player.
That's not for me to answer, but for Apple I guess. Maybe someone who works there can shine a light on this. Speculation about the URL bit would probably center on Apple tending to put form over function. Promoting Apple News -> because it cost them a lot of money to get it in the first place and they are trying to recoup that money. Not that I would ever even look at it, I don't think a hardware manufacturer is the best place to get my news fix.