It's pretty much all there, it just needs to be packaged.
Also most people don't like carrying a compass and road atlas like I do so the turn by turn navigation needs to work (KDE marble will stick you on a slippy map and route for you but I don't think it does real time navigation right now.)
Linux Apps don't benefit much from the fancy GPUs unless you're running eg wayland. If you're mostly using Xterm, muPDF, Firefox etc. the GPU on the original is plenty fast.
You might try experimenting with different configurations. With a lightweight X11 WM on PMOS Firefox takes ~10 seconds to load cold for me (and it's closer to 4 if I've just killed it.)
But it's fast enough. Since you can use overlapping WMs you're not stuck staring at loading screens and can use other apps while you're waiting with no time spent switching. Android is heavy. It's way worse than people realize.
>Short battery life
You can fix this by adding an extra run level that uses RTCWake to sleep the phone when it's "locked" without missing notifications. I think a number of distros have added this.
Also you can swap out batteries unlike nearly every other phone. They even sell a charger. I have three that I cycle through.
>Buggy
IME it's better than Android now.
EDIT: Well, let me clarify this. You will have to tolerate some bugs, the EG-25 modem firmware is particularly bad. I use VOIP for MMS and voice because I don't trust the modem to behave. Everything else (the stuff the community actually controls) is better than Android though in my opinion.
Well there are volunteer groups that add extra packages to these distros and build images for them (mobian -> debian, alarm -> arch, PMOS -> alpine.) I think a lot of it will get upstreamed to Debian (if it hasn't already.)
On mine I run PMOS configured nearly the same way I have my other computers configured (same WM and everything.)