To first approximation, we are. Essentially all mobile networks are IPv6 now. Many wired client drops are IPv4 NAT behind an IPv6 pipe. Most datacenter-inter

To first approximation, we are. Essentially all mobile networks are IPv6 now. Many wired client drops are IPv4 NAT behind an IPv6 pipe. Most datacenter-internal communication is IPv6, at least at the big players. The only regime that is still "IPv4-by-default" is public facing servers, which (obviously) still need to present the old addresses for compatibility. But that last 5% will still be around until we all die. There are just too many client devices out there that will never get an IPv6 update, and client devices tend to live much, much longer than you (or their designers!) think they should.