You say "often" - can you give some examples? The only changes the general public - that would be me - is aware of were actually in favor of developers: the change from 30% to 15% after 1 year of a subscription.A contract that Apple can, and often does, unilaterally adjust and modify as they see fit. That's not a contract. It's coercion — because developers cannot pull out anymore once investments have been made into an iOS App.
Apple has turned hostile towards developers and as a result, hostile towards consumers. I want choice. I want freedom. I want to decide what I can put on my phone. Not Apple.