Adoption has increased, and will continue to increase, as there is more and more of a need for it to.
Instead, here we are 26 years later, and the adoption rate looks like this: https://stats.labs.apnic.net/ipv6
That says everything about IPv6 that needs to be said.
> Because it was incredibly stupid not to make IPv6 backwards compatible.
Without providing a non-stupid solution to a problem not solved for decades, and likely not solvable. (Also I assume you meant ipv4 forward compatible, you can name ipv4 hosts on ipv6)
It's only a question of time.