In the US, I really want the FCC to mandate that an ISP provides IPv6 connectivity in order to meet the criteria to be considered broadband (and access the subsidies related to that). Don't even care if the functionality is off by default / you have to call and agree the routing may be sub-optimal, whatever. I currently use HE tunnels but on top of additional latency, the HE <-> Cogent peering dispute still makes it difficult to access services over IPv6.

Nah, we just need actual carrots. If something new is better than what people currently have, and you make it easy for them to get the new thing, people will naturally abandon the old thing. They'll do it happily. In fact, it will be hard to stop them from abandoning the old thing for the new thing.

IPv6 has failed at being better, being accessible, or both. Rather than punish people for failing to adopt something that isn't better or easy to get, either improve IPv6 so that it's actually attractive or admit defeat and start work on the next version that people will genuinely want.

The moment you start thinking "Let's make what people have now worse until they move to this other thing they don't want" its an admission that whatever you're pushing people to is shit.

The US government is pushing IPv6 for government sites and contractors.

I think there needs to be a push for IPv6-first networks for companies. ISPs in the US are pretty good about IPv6. But network engineers learned IPv4, and don't want to change what works, so companies lag behind. Changing existing networks is hard, but IPv6 is good candidate for new networks. This includes writing docs and eventually the education so IPv6 is the default.

Or we should start a wall of shame of services not available on IPv6.