I think I agree with you, but it's interesting because you're actually making two points which are kind of the opposite of each other— on the one hand arguing that it's hard to pay the 30% before costs are recouped, but then also arguing that it's unfair to pay the 30% in perpetuity long after Apple's fixed costs (review, etc) have been recouped.

I think if anything this kind of thing makes the case for explicitly having multiple tracks— maybe an enterprise one where you pay a 5-7 figure fixed annual fee (for support, timely review, policing of the store for phishing/knockoff apps that target your own, ensuring a direct hit for explicit searches) and then either a single-digit percentage of revenue or for free "portal" apps, some other way that Apple is compensated for user engagement. And then a totally separate indie track where all the revenue is yours up to X, after which some kind of sliding scale kicks in.

In reality, there are almost certainly enterprise deals going on behind the scenes (or at least mostly behind the scenes, cough Epic) and the details of those are almost certainly very proprietary, due to how the negotiations would occur. But having at least one option for which the details are public would be nice.