Everybody should be using it, but nobody does.
Not nobody but certainly a lot less than is desirable.
This has been the steady state for what, 20 years?
Unfortunately people don't do stuff until there is real pressure to do so. As the IPv4 crunch has started to bite harder providers have started to take IPv6 more seriously. Theres still a long way to go but there has been a real increase in adoption over the past few years. https://www.google.com/intl/en...
We probably should re-do the thing and skip to IPv9 with a less grandiose than this second system but a nice and functional third.
Yes the IPv6 proponents had some grandiose but half-baked ideas. To name a few Heirachical routing, abandonment of NAT, mandatory IPsec, site local addresses, A6 and DNAME, Stateless mac-address based autoconfiguration.
But yet another new system isn't going to help anyone, the problems can and have been solved while keeping the core protocol compatible.
The heirachical routing crap has already been dropped in favor of using the same routing methods as are used for IPv4. A6 and DNAME have been abandoned in favour of letting companies get PI space like they can for IPv4. NAT is still discouraged but there are implementations available for those who want/need it and protocols have been put in place to delegate prefixes to customer networks automatically. Mandatory ipsec has been abandoned. Site local addresses have been replaced by the far more sensible "unique local addresses" which acknowlage that "site" is an ill-defined concept. Mechanisms have been put in place that allow running a V6 only access network while still providing limited IPv4 functionality for clients (there are two competing options for this DS-Lite and NAT64) . We have privacy extensions to avoid MAC address based tracking with stateless autoconfiguration or alteratively you can use DHCPv6 instead.
Perhaps with a different crew this time. That'd be nice.
I think we already have a different crew, we now have people who work at real ISPs designing IPv6 soloutions that really work.