This Linux phone with Android app support has three kill switches for complete privacy
(www.yankodesign.com)
Yes, I mean the 2018 era SDM845 bunch of phones. They mostly work. While postmarketOS is the community that made linux on phones possible, it is not the only thing that you can run on these, there is actual choice. I personally liked Mobian very much.
Making linux phones more widely adopted will require wider community interest and halium is just not the way forward.
Edit: screenshot to illustrate my point, my OnePlus 6T running NixOS in UEFI mode (based on this writeup by /u/chayleaf@lemmy.ml:
spoiler