This is essentially the model of App Stores. And it works. At least to keep the worst off Apples App Store. Mostly. Googles play store is apparently much more

This is essentially the model of App Stores. And it works. At least to keep the worst off Apples App Store. Mostly. Googles play store is apparently much more linient. And contains lots of horrible apps. But the costs, as you mention, are real too. So much, that many, including myself, simply forego Apple as target at first. Sure, it's the more popular platform and it has more people willing to pay. But the review hurdles aren't worth it in the beginning.