Earlier quoted context omitted.
LineageOS is supported on a bit more devices, and works with microG if you're willing to sacrifice Google Pay for better battery life and less privacy violations: https://lineage.microg.org/
This worked ok, but wasn't as nice as grapheneos' solution so I ended up upgrading to a pixel once my cheap chinesium phone was sufficiently old and haven't looked back since. If you do the microg route you should be using a throw away gmail account you don't care about losing with the aurora store (if you need access to the google play store) because there is a non zero chance they ban your account.
They also have a pool of accounts you can use by clicking “anonymous”. They do get banned frequently, and you have to re-login once in a while (for me it's almost every time I want to download something new again), but it is definitely usable.