It's fine if they want don't want to implement everything.
The point is that if they don't get to simultaneously say:
1. The Web is a viable way to compete with native apps (which they explicitly said in defense in a current court case).
2. While not implementing features necessary to compete.
3. While not allowing anyone else to build a browser for iOS that implements the features necessary to compete.
I think we could have those API only enabled for Web Apps and not within Safari. But then Apple want to push everything to native App. Which is fine if it wasn't for the curation of App Store which has some benefits and problems.
It's fine if they want don't want to implement everything.
The point is that if they don't get to simultaneously say:
1. The Web is a viable way to compete with native apps (which they explicitly said in defense in a current court case). 2. While not implementing features necessary to compete. 3. While not allowing anyone else to build a browser for iOS that implements the features necessary to compete.