Honestly not sure why my comment is being downvoted. IPv6 became a standard in 1998. If it had been backwards compatible, it would have been adopted in just a few years.

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 you're saying things like

> 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)

Because it gets repeated on every thread on IPv6. IPv6 is perfectly backwards-compatible with IPv4 (you can run an IPv6-only host and still access hosts from the IPv4-internet). The issue however is that IPv4 is not forwards compatible. IPv4-only hosts cannot initiate communication with next gen protocol only hosts by design.

IPv6 adoption is a monotonously increasing curve (ignoring daily fluctuations): https://www.google.com/intl/en/ipv6/statistics.html

It's only a question of time.