I've had "native" IPv6 service for something like twenty years. I've not had a problem with accessing any of the internet.

If you're hinting that roughly half of the internet-connected servers don't have IPv6 addresses, then my reply is "so what?". Only idiots are suggesting that folks who aren't running an experimental lab (or ISPs that have the expertise required to set up the NATs needed to reach the IPv4 internet from v6-only service) go IPv6-only.

I think they did in fact mean IPv6-only hosts. For instance, you can save some money getting a virtual box on Hetzner that doesn't have IPv4 connectivity. Of course, that box won't be able to talk to ex. github, so for some people it's really not worth it.