To the extent that the walled garden keeps quality up, I'm all for it as a user, and in agreement with you. I'm all for Apple clamping down on apps that crash, violate privacy, drain the battery, deceptively advertise prices, and so on.
But I don't see how I benefit from some of Apple's moves, such as stealing 30% of developers' revenues [1] when their own apps don't have to suffer this tax, or Apple Music spamming me via push notification ads while others are forbidden from doing so. Or taking down apps that mention that they also support Android. All of these are in Apple's benefit, and against mine.
In 2008, I gave the benefit of doubt to walled gardens. In 2020, it's clear that they need government regulation to stop abusing both users and developers, which a monopolist otherwise tends to do. Walled gardens are still a good idea for people like you and me, but need to be controlled.
[1] When I've already paid through my nose for Apple's overpriced devices.