I got a pixel 4a and put grapheneOS on it with a bunch of FOSS apps sourced from recommendations of the awesome people here. Actually remarkably little hassle, although transferring contacts was a pain in the arse. I always find with privacy/FOSS/non-mainstream computer stuff its all well and good at the start when I still have the energy for it but six months down the line shit breaks and needs weird manual updates and I really can't be bothered so it becomes increasingly unusable, but this seems remarkably streamlined so I guess it's kinda a good balance?

Felt suuuuuuuuuper dirty giving money to google but I'd rather that than giving them all my data

But it works well, and its pretty much the only phone available that isnt ridiculously oversized

I know nothing about the pinephone, but there's my experience anyway fwiw