I don't think the 30% has ever been an issue. The exclusivity is. Doubly so as Apple keeps changing the rules which if you're caught on the wrong side of can destroy your business.
Not because of the percentage, but because of the exclusivity. 30% on in-app purchases/subscriptions was only a big deal because Apple required that you use it and match the lowest price anywhere else. (They since backed down on this, but they can change their minds again.)
You can't distribute an iOS app outside of the App Store (outside of the enterprise). So Apple's 30% fee is essentially a tax on iOS apps--there's not a way around it.
Apple can destroy your business by changing a rule that makes your app ineligible for the App Store (or at least unprofitable, most recently seen in the whole in-app fiasco). There's not a way to distribute outside of Apple, so if Apple doesn't want to distribute your app then you have no business.