#GrapheneOS is state of the art and easy to install, but you need a Google fone to install it. So this solution is expensive and you are on Google hardware. If you have an older fone, check if it is supported by #LineageOS or #CalyxOS, in combination with a App separator, firewall, VPNs and DNS resolver software on your fone like #Island or #Insular or #Shelter ; #AFWall+ : #AdAway or #DNS66 or #TrackerControl ; maybe #MullvadVPN