alt Hacker News> IPv6 will never reach the 100% needed to turn off IPv4.
As was predicted in 1994:
Furthermore, we note that, in all probability, there will be IPv4
hosts on the Internet effectively forever. IPng must provide
mechanisms to allow these hosts to communicate, even after IPng
has become the dominant network layer protocol in the Internet.
It was also predicted that the address exhaustion problem would be averted, in fact that was the purpose of v6. It failed to deliver.