Are you aware of the PinePhone and Librem 5? As others have said, it's already been tried.

I bought a PinePhone, and after a few too many show-stopping issues (not being able to receive a call for a scheduled job interview was the last straw), I went back to using LineageOS without gapps. I'm not a developer either, just a fairly technical user, so when the device wasn't working, all I could do was report bugs, and things weren't improving fast enough. I haven't checked on progress in a while now. postmarketOS seemed like the one to follow, and they do also support some beefier devices like the OnePlus 6T, but then you'd miss out on the PinePhone's ability to easily remove the battery and to boot off the SD card in addition to eMMC.

I also felt a bit bait-and-switched that the PinePhone Pro came out not too long after the original and then everyone seemed to switch to that one. It reminded me of the awful Gemini PDA and how quickly they rushed out a successor without fixing any problems.

> after a few too many show-stopping issues (not being able to receive a call for a scheduled job interview was the last straw)

When was it? There are no complains from people daily driving both phones in the last couple of years AFAIK.

Don’t worry, the PinePhone Pro is now EOL while the original one will go on for 2 more years!!!