I disagree with you here. I think there should be some relationship between the value that Apple provides in a transaction and the fees they take. If you're a small indie developer publishing your pomodoro app or whatever, maybe 30% is reasonable - Apple does payment processing, handles refunds, pushes updates, and provides a certain level of marketing for your app (and I think Apple takes 15% for small indies now, which definitely seems reasonable.)
For something like Patreon, though, Apple being in the transaction provides little value. Patreon is a company that takes donations from individuals and gives them to individual creators, making it basically a financial services company. A small cut for payment processing is reasonable, but 30% is not. That would be very similar to Apple wanting a 30% cut when you send your buddy $5 via Apple Pay.
More generally, I think Apple should be pressured to be good stewards of the system they created and I don't see anything wrong with that.