Apple's been consistent: digital goods and services.
The debate with Facebook reported in WSJ back in August (https://www.wsj.com/articles/inside-the-apple-vs-facebook-pr...) Apple was saying "boosts" are a service to raise the profile of your dating profile or media posts, while FB was saying they were ads to avoid paying for them. All other apps (TikTok and the dating apps) consider it a service, only FB/Insta were playing this game.
This clarification shouldn't have been necessary, FB was playing a game, and Apple closed the loophole.
> unbelievably high
It's not unbelievably high, go have a look at what any platform charges. Also, remember the rate drops in year two, and for those making less than a threshold, etc. etc., so it's not 30%, it's considerably less overall.
They'll take it as far as necessary to to make the same off providing app store services any platform makes for distribution, such as Steam makes off providing Steam.
The problem with IAP is that at 0% for the app itself, Apple cannot offset the costs of the platform they are providing for distribution. So if they take their cut off app sales, then apps give themselves away for free, and charge the price as an IAP, Apple's stuck. They have no choice but to take it off IAP.