Yes, it's all true but the issue is you can already do a lot of those things with a lot of cheap hardware that is is simply easier to support than old phones. And when it comes to phones being phones Android is really good and has a lot of apps. I think the problem with Linux phones getting more popular is that the overlap between desktop/server and mobile is very small. I mean I use my phone only for phone things and a lot of things I do on my phone I can do only on my phone (e.g. charging an electric car is basically impossible without a Android/iPhone). Having a phone that can do some things desktop/server can do but can't do a lot of things a phone can do is pretty much pointless at this point.
When we'll get a proper Linux phone with full Android apps support and convergence it will be really awesome but I just don't think there's enough interest to get there at this point.
I know and what I'm saying is that all those project are moving very slowly while projects like GraphneOS/LineageOS already offer open, privacy oriented phones with good hardware and lot's of apps. This is simply where more effort is going, where we're seeing more progress and our best chance at getting "Linux phones".