I'm not saying Apple don't provide a service, of course they do, though at times it sucks. My main point is about is about the price, not the principle. I pay Apple a yearly subscription just to develop for their platform. On top of that every sale I make they get 30%.
Would 95% be ok?
Another extreme element of this is that I cannot sell a licence outside of the App Store to my customers. I cannot ask them to buy from my website (which many have asked about and would be happy to do) and provide them with a code they can use to unlock or upgrade. This is explicitly banned. Unless you're a big player like Spotify or Netflix your app will not be allowed to do this. I've tried and been denied and stonewalled.
In this case I am willing to build and manage my own payment/licencing setup to gain 30%. I'm just not allowed to do that.