but Apple isn't commandeering the content itself like Google is Content authors voluntarily publish their content in AMP form, so it doesn't seem fair to say t

but Apple isn't commandeering the content itself like Google is Content authors voluntarily publish their content in AMP form, so it doesn't seem fair to say that they commandeer anything: AMP is a subset of HTML intended for a fast mobile experience, and if you decide to take part you publish flags allowing Google to cache it. Google isn't unilaterally converting content to AMP. The core argument against AMP primarily seems to be a fear that users will actually prefer AMP content. Which is ultimately rather anti-user.