Apple can afford to implement anything they want. But they clearly have a very strong business interest in not letting web apps gain all the features that nativ

Apple can afford to implement anything they want. But they clearly have a very strong business interest in not letting web apps gain all the features that native apps may have. Also, there is no legal requirement to implement every single API that the standards body specifies. The point of having standards is to make sure that _if_ a browser maker decides to provide some functionality, then they can implement the standardised API rather than inventing their own. This is a good thing in spite of the fact that it doesn't solve other problems related to market dominance.