If you’re ok with 10% fees, you’ll do well to get an App Store like 30%. And if 30% fees drives off half the freelancers so what?

Freelancing and product development are two different things.

Also, getting an app in an App store requires a high-risk investment.

Further, I wouldn't want to support Apple's developer-unfriendly ecosystem.

Rent extraction is only one thing however.

find a subcontracting firm, and get in there. I've worked with a couple, and while they don't tell me what they bill me out at, in one case I was pretty sure there was a 20% buffer they'd built in. I suspect in other cases it's probably more like 25-30% - you'll get billed out at $100/hr, but they'll pay you $70/hr. But in those cases you don't own the relationship, nor necessarily have much visibility in to the business relationship. You're just a pair of hands at that point.