> Are Google so high on their own supply that they think people use their phones out of preference for the OS? Because frankly it's not very good

Honestly having gone back and forth between iOS and Android every three years or so, both OS are the same. It's not like the grass is really greener on the Apple side. The UX is virtually identical for anything that matters. Personally I put material Android above liquid glass iOS. The alleged polish of the Apple UX was lost on me when I had my last iphone.

The reason Google's moves are surprising has more to do with them embracing being a service player more and more with the arrival of Gemini and them having regulators breathing down their necks everywhere.

I guess they did it after the truly baffling US decision in the Epic trial but it's very likely to go against them in the EU.

The rumors that I have heard (and one government document I read that was poorly translated from Thai) is that there are some countries who are pressuring Google on this to combat info-stealing malware. Apparently, account-takeover/theft is very prevalent in SE Asia where most banking is done via Android phones.