The sad thing is that's probably why IPv6 is never going to be a thing. Why would all major tech companies be willing to write off such expensive assets?
They can try and resist. But they will lose. For example: I've set up a IP6-only backend because it was easier than getting IP4-connectivity. And when I tried Travis and they couldn't connect to that backend, I dropped Travis immediately. That is still uncommon, but I'm sure I'm not the only one who's made a decision in that direction.