Google, by contrast, has a far larger share of the search engine market than Apple has of the mobile device market. That means it's more of a concern by default.
If we are talking about search, you can stop using google by typing bing.com or duckduckgo.com in your url bar any time you want, and every major browser supports changing the default search engine, even Chrome.
However they ship it, they'd still be in an arms race against google to keep AMP pages hidden from Safari users. That doesn't seem like a productive use of anyone's time.