Every few months I turn on IPv6 at my house. I try to use it. I find random sites just not working, random delays accessing sites, and so on. Then I switch back to IPv4 and everything works.
I used to be a network admin, so I know how to configure networks. IPv6 zealots accuse me of incorrect config, doing it wrong, etc. Maybe that is the case, but if I, a sophisticated user, can't get it working well, what chance does a non-technical person have?
My assumption is they just deal with the issues and chalk it up to "technology sucks". But I know better. I've experienced the internet when it works, and I know when it isn't working right.
I think IPv6 is better in theory, and I look forward to the day that it is in practice. But today is not that day.