> It's not the tech for the most part... it's how Amazon is using it

Yeah, so I mean if Amazon then developers their own framework + OS on top of React Native, how well do we think that'll go, if they're unable to use things well?

If I were to guess, they aren't heavily modifying anything... it's likely a fork from Android and supporting React Native as a primary tool towards developers. I honestly doubt they've actually "done" much of anything other than branding and packaging.

Fire OS was an Android fork. Best I can tell from the stuff I've seen in the news about it, is that Vega OS is not Android at all, and is completely custom (well minus the Linux kernel)