Graphene is not for all old androids. lineageos is compatible with almost everything https://wiki.lineageos.org/devices/
Discussion
I like LineageOS, but it's also much less secure than Graphene
I'm (reluctantly) getting another phone after getting fed up with the data loss I incurred on the Pixel and giving it to my younger brother, on top of dealing with shitty refurbs that are NOT from Swappa or Backmarket; after this phone, I'm not getting another for the next two years and will hopefully not lose as much data this go around.
It's a moto edge+ (2023), and with how notorious Lenovo-owned Motorola are with updates, the moment security patches stop flowing in, Lineage will drop in and carry on.