> ... but I think ipv6 is inherently more complicated than ipv4 for the average use case. It's not just a thinking shift.

IPv6 isn't all that complicated for most common use cases. Its fundamental concepts and rules are simple. It also obviates the necessity of the complicated workaround called NAT, without which IPv4 is impractical these days.

It's more like the imperial vs metric system debate. If the world hadn't seen IPv4, I believe that we'd all be using IPv6 without any complaints. The real problem is that IPv6 isn't taught well.

> Separate from that, deliberate decisions were made to make it a "clean slate" without consideration for existing ipv4 hosts. Guess they were hoping the separate stacks would go away eventually, but in hindsight, no way.

I'm not sure what to make of this. The presence of the IPv4 stack isn't what blocks the adoption of IPv6 - at least not technically. They can coexist on the same host and function concurrently without interfering with each other. It was designed to operate like that. The actual blocker is the attitude that people hold towards IPv6 - "We have IPv4 that works already. Why should we care about an alternative?". You can see that expressed on this discussion thread itself.

There is one crucial detail that the IPv6 detractors neglect - the scarcity of IPv4 addresses means that IPv4 address blocks are now heavily coveted and therefore subject to moneyed interests. That isn't very good for the health of the open internet, digital rights and equity. They're thinking about individual trees and losing sight of the whole damn forest. IPv6 isn't a solution looking for a problem. It's the solution for a problem that people simply ignore.

ipv6 would have been a breaking change anyway, just take the opportunity to push through any changes that they want to make