I love your optimism. What you'll see is return to 2000s where you may have had "Symbian" as the operating system, but the phones weren't compatible between themselves and apps broke and didn't work across manufacturers (or even product lines) because there was noone enforcing compatibility.

I wonder if you forgot that or you're too young to remember what kind of bizarre hell mobile development was at that time.

Heck, even early Android was really hard to develop for because CTS suite didn't cover enough and all of us spent hours upon hours (and many dollars) trying to reproduce and fix Samsung, Huawei, HTC and other bugs.

I doubt that people advocating for GrapheneOS would pivot to a Chinese powered platform.