I absolutely do not want that to happen. This is no way is an actual benefit to anyone. If Hey or ClassPass was relegated to some other app store on iOS, it may as well not exist.
It's an actual benefit to anybody who is willing to jump through one tiny hoop to get the app they want, and an actual benefit to the developers of those apps.
The result is that Apple has to actually be competitive with its App Store. A lot of these BS policies wouldn't last if they had to be competitive.
And if Hey is typical of the vast majority of SAAS services, they pay affiliate fees and other marketing fees based on a percentage of sales to third parties that promote their service. So why not play Apple their 15% for a seamless in-app purchase system to add new users with?
Hey has responded very specifically to this https://hey.com/apple/iap/
Their main objection to this is that they want to own the relationship with the customer. They want to be able to issue a refund or account credit or discount or hardship exceptions, which you cannot do through Apple's App Store.
If they had their app distributed elsewhere and they were losing customers, they could choose to work with apple, but right now they have no choice. At the same time, apple would have to earn its relationship with developers like target and Walmart have to do with their suppliers.
There are plenty of companies and individuals that have chosen to direct-sell rather than offer products through other retailers. It's a choice they can make, foolish or not.
If I'm a parent, I would love to be able to enable an app store that sells human-curated child-friendly apps with no advertising and strict controls over tracking. I'd like that store to be a heck of a lot stricter than Apple's is.
Apple can't offer me that level of quality, because the same store needs to serve multiple demographics. Sure, they can flag some apps as mature, but the fact that they're balancing that distinction to try and come up with a set of standards that will be acceptable to everyone across multiple continents means it's very difficult for them to make gut-level instinctual choices or take hardline positions on what they consider acceptable.
The same is true for security. Apple has standards about what info apps are allowed to access, and they'll throw apps out for requesting permissions that are unnecessary. But I'm going to be honest -- their standards are lower than mine are. If I was building a privacy-respecting app store, it would be way stricter than Apple's.
Having choices gives you the freedom to opt into stores that are strictly regulated and curated on a quality level that Apple will never be able to approach. No single app store that's designed for everyone will ever be as well moderated as a set of distinct stores that are serving specific niches.
Apple has built a secure system, but that is only secure if you trust apple (i.e. one software update could break a secure enclave). The next question is, can the system still be secure, but the trust decentralized. This is complicated and hard, but I would say it is not impossible