I think the crucial issue here is Android app compatibility. Desktop Linux programs aren't suited for use on mobile devices; the experience is inevitably poor. Android compatibility is claimed, but no information beyond that is provided. If this device does not run at the very least any app that does not depend on Google Play, e.g. apps from F-Droid, it's dead on arrival. In that case, you are much better off with a Pixel running GrapheneOS. Graphene is very polished and has 100% compatibility with Android. Everything just works and the user experience is as good as an official Android device, only free of Google spyware.

"I think the crucial issue here is Android app compatibility ..."

I thought there was a robust android emulator for linux such that I could run android apps - and call an Uber or whatever - from desktop linux ...

Is that not so ?

Yeah everything works except payment, and banking apps, and probably some other stuff. Considering Google's policy direction this isn't going to improve sadly

And let's be honest, it's not like there hasn't been spent a decade or more, with thousands of developers working tirelessly on making Android as good as it is today. Like linux laptops not burning up immediately is itself a change upstreamed from android development, but that's just half of the story.

A mobile OS fundamentally needs a different application model -- apps can't just decide to run whenever they like. How will desktop GIMP know that it shouldn't waste my battery when in the background (unless it very specially requests it throuhg an API made just for that)? Does suspending it work as you expect? For how long will you suspend it, shouldn't you kill it as well after a while? Who saves stuff?

I can't help but feel that anyone strongly advocating for a GNU Linux phone (because let's be honest, Android is the linux phone) is just not familiar with the actual context of what it entails.