The linked essay is quite long and (at least for me) hard to read. One of the first links in the article is to this patreon blog post, that summarizes the issue well.
As we first announced last year, Apple is requiring that Patreon use their in-app purchasing system and remove all other billing systems from the Patreon iOS app by November 2024.
This has two major consequences for creators:
Apple will be applying their 30% App Store fee to all new memberships purchased in the Patreon iOS app, in addition to anything bought in your Patreon shop.
Any creator currently on first-of-the-month or per-creation billing plans will have to switch over to subscription billing to continue earning in the iOS app, because that’s the only billing type Apple’s in-app purchase system supports.
Before we go any further, we want to be crystal clear about one thing: Apple’s fee will not impact your existing members. It will only affect new memberships purchased in the iOS app from November onward.