So weird to see a demand for adherence to open standards justified by... the desire to see Apple preserve the dominance of its decidedly-closed device ecosystem.
Agreed it's weird. But it's not the justification in general.
Apple is so accustomed to leveraging proprietary stranglehold, including sometimes being an outright totalitarian, that they need to realize the precariousness of their position of strength, and learn why most other parties have to at least pretend to believe in non-proprietary interoperation.
A school bully shouldn't wait until they get a debilitating sports injury, and they are suddenly the one getting stuffed into the trash cans, to start preaching&practicing the good word that no one should be stuffed into trash cans.
Life is weird. And in this weird case, Apple’s monopolistic insistence on denying other rendering engines on its phone has prevented the web from devolving into a monoculture.