Every time somebody says "I don't want vendor lock-in", they flip it to "Oh, so you don't want safety?"
But these are often false dichotomies created by Apple. Reviewing and rejecting apps for fraud and malware is great, but Apple bundled that with rejecting apps for using the word "Android" and whatever other curation they want.
Having built-in first-party subscriptions UI is safe and convenient for users, but the mobile duopoly and their control of the platform lets them charge for it whatever they want. Apple implies that allowing other payment processors means going to a dodgy website that makes unsubscribing and refunds impossible, but that's a false dichotomy Apple has created. They could require integration with iOS's subscription management APIs to use alternative payment processors (they already support PayPal as a back-end).
And this is another case where it's incredibly convenient that opening up internal APIs without safeguards to 3rd parties would be unsafe, so they haven't done it. But this is a false dichotomy – they don't have to run 3rd party browsers unsandboxed, or allow any app create homescreen icons willy-nilly. Adding to home screen is already a user gesture through the Share sheet, mediated by the OS. Browsers must be sandboxed anyway, and webapps were already allowed to run full screen.
And this isn't lack of just any feature. Apple has argued for years that App Store isn't mandatory, because anybody can just make a web app instead. That was never quite true do to Safari's limitations, but now is just a farce.