I think /e/ looks promising.
Good to hear that some others have had success with Lineage. The sticky bit for me is that my phone is not on the official support list. I read that I can probably make it work, but I am expecting some major feature doesn't work, otherwise it would be listed.
/e/ sells refurbished phones preinstalled, which I think is a great idea. Only shipping in Europe right now, and they were ~ €450
Buying a working phone is a good move. Mainly because I need to have a spare before I try something like this anyway.
Mainline hardware that isn't locked down usually gets attention quickly. If you don't mind hanging out in the wind, you can give an unofficial build a go.
https://forum.xda-developers.com/pixel-2/development/rom-lineageos-16-0-t389...