Sadly, Apple has demonstrated this kind of oligarchy in the past. This was always inevitable, just up to them when to pull the plug. And this is yet again why I will never purchase an Apple product, no matter what kind of cult following they have or how good some apps may be. I won't waste my money on them, or support them.

I would focus on sideloading, consider a web based PWA approach, and diversify into Android with a focus on compatibility with alternate OSes like Graphene. Diversify, and fight them with the market, not by bending the knee and playing the game by their rules. They do this shit because people let them get away with it, yet still support them.