There's plenty of digital goods with low margins that apple forces a 30% cut.

e.g. Spotify, Twitch, Patreon etc. Most of the funds go to the creator. Completely breaks the model when Apple forces a 30% cut of gross.

That being said, i'd also argue Apple's app store is a complete monopoly on iPhones. Iphones and app stores are such an essential part of life, they deserve to be neutral a la internet neutrality. Not sure how we all become pro internet neutrality but somehow suffer Apple's 30% tax.