It's interesting to see how Google has gone from seemly uninterested in IPv6 (based on that quote from 2002) to today where it uses it everywhere.
As an example, it's one of the only large providers I've seen that will send and accept email over IPv6. This is contrast to others who refuse on the basis their anti-abuse techniques don't work in the larger IPv6 address space [1]
I think companies like Microsoft (which, let's be real, is the only other "large provider" when it comes to email) are afraid of breaking configurations and undeliverable mail because of bad IPv6 setups. MS isn't known for adopting anything quickly, especially when it comes to enterprise services.
The many old techs and their advocacy against IPv6 because they don't (want to) understand it will influence the web for years to come, but in reality you can enable IPv6 anywhere and things will work just fine, as long as you don't do stupid things like disabling all firewalls. Docker has some trouble working well with IPv6, but an IPv6-capable host with an nginx proxy will nip that problem right in the bud, and you're (hopefully) not using a publicly reachable IPv4 Docker network anyway.
[1]: https://www.cnet.com/news/google-tries-to-break-ipv6-logjam-...
https://cloud.google.com/compute/docs/ip-addresses/configure...