[Dagger2]

There were always expected to be v4 hosts on the Internet effectively indefinitely. That's not a failure condition for v6.

"There are a couple of v4-only hosts out there somewhere" would be kind of irrelevant if most ISPs stop bothering to provide v4 service.

[tgma]

It won't be just a couple. That's the point.

The curve is at 50% after an astonishingly long time and is already flattening.