> So when Apple introduces new features and frameworks, should developers then pay Apple?

They already do, in the form of a couple subscriptions. A fixed one of $99/year and another one which is a tax of 30% on their revenue.

And they could pay more if Apple never made breaking changes.

>> - Developers should get a “cut” whenever Apple makes arbitrary changes that completely break 3rd-party apps. If the app’s code doesn’t change but Apple does change something, their behavior is literally creating problems for developers with no cost to Apple. Let’s charge them!

> So when Apple introduces new features and frameworks, should developers then pay Apple? This doesn't seem to make sense.

I thought so too at first but that brings back one idea I had that most independent software vendors will probably hate and puts more control in Apple's hands but here it is anyway:

Apple can add a way for developers to submit source code, assets, and machine readable build instructions in an Apple supplied format. Apple then builds the bits that goes on the App Store. Developers already pay USD 100 a year for the privilege of being on the App Store anyway, right?

This way, if Apple introduces new features and frameworks, they can automatically update the code as needed and push updates to the users?

Then Apple could steal dev IP.