It might be, but you can make same argument about any curated platform.
I also don't think this serves the public interest. App developers have much less interest in maintaining the privacy of users and making it easy to cancel subscriptions, among other things.
This is a difficult issue because it involves restricting the freedom of a service provider to develop their product as they see fit. Ideally, the market itself should force companies to make things that are beneficial to the customers. Unfortunately, real customers can be manipulated, that is why there are regulations. I don't have a good answer to why there needs to be a regulation in this case, but it wouldn't be the first.
As I mentioned in another reply, both Apple and Google, despite not being monopolists, can arbitrarily restrict competition, because they have the power to refuse serving some apps. I would argue that it is dangerous, and corporations should not have that kind of power.
I also don't think this serves the public interest. App developers have much less interest in maintaining the privacy of users and making it easy to cancel subscriptions, among other things.