Curious: Would there be any benefit to open sourcing parts of the OS, at least enough so that it could run on mobile hardware of some kind?

I believe HP/Palm open-sourced WebOS after they abandoned the device market, but nobody tried to build a Hackintosh type phone out of it.

Back then, that made sense as WebOS suffered from a lack of apps, but in 2019, mobile web apps aren't the afterthought they used to be. I can call an Uber and track the entire journey using their web app manifest ("Add to home screen"). I'm using Uber as an example of a complex app that you wouldn't think would work well as a 'website'.

With everything we know about Google's data collection/tracking policies, I'd think there'd be some itnerest in having the option of hardware that ran a non-intrusive mobile OS.