Android has had support for IPv6 since at least 2014, and there are plenty of mobile networks which are IPv6-only and work just fine with Android phones doing C

Android has had support for IPv6 since at least 2014, and there are plenty of mobile networks which are IPv6-only and work just fine with Android phones doing CLAT. The only thing missing is DHCPv6, and that's a deliberate decision - albeit a somewhat controversial one.