Oddbean new post about login | logout GrapheneOS runs only on google pixels. So you could get a used pixe,l 6a or 7a are quite good. Don't know if the series 5 still gets security updates.
I read a bit about security updates. That the device stops getting those updates based on their regular schedule. Would be cool if they kept going with Graphene but it is what is
Good to know. Then not older then the 6er series.