The problems you talk about are deliberately created by Apple and only fixable by Apple. If you buy an iOS device you're opting in to whatever bullshit Apple comes up with that isn't explicitly regulated away, and when regulation is introduced Apple has made clear that they will do whatever they can to avoid complying with the spirit of said regulation.
The creator of Delta is pushing the first regulation-protected route they have for distributing their app. You started this thread saying you wish they didn't.
Dealing with notarization, timeouts, yearly developer account subscriptions, it's all terrible. The only hope to ever get away from it is to put up with as little of it as possible, which currently means an alternative app store. Or you can stop buying Apple devices.
Sounds like you're going to be in the business of fielding unpopular opinions for quite some time. I'm shocked that someone would shake their fist at the person developing code that you can go download right now[0] and not the business that prevents your phone from using it. If this is your sincere opinion, you either misunderstand the situation or expect to have your cake and eat it too.
What you're saying is that you are not interested in solving what you describe as "The key problem with iOS app distribution".
I am not claiming Android is perfect in any way; I don't think a truly good usable mobile option exists. I will claim that the differences in quality are minor in comparison to the problematic level of control Apple exercises over iOS.
The creator of Delta is pushing the first regulation-protected route they have for distributing their app. You started this thread saying you wish they didn't.
Dealing with notarization, timeouts, yearly developer account subscriptions, it's all terrible. The only hope to ever get away from it is to put up with as little of it as possible, which currently means an alternative app store. Or you can stop buying Apple devices.