I agree that we need a full and complete understanding rather than a simplistic one. miki123211's response adds to that, but a fuller picture is that

- companies were using IOS to serve a legitimate need that Apple did not.

- As noted this was done by subverting an API

- Apple tolerated this (did they not know or not care or ?)

- Apple released a competitive product with a new API

- Apple begins removing products using the old methods

The question is whether Apple is allowing existing products to migrate to the new API or are they locked out? If existing products cannot use the same API then my sense is that Apple is indeed being anti-competitive.