[srj]

The network virtualization scheme and likely many other parts of the stack need to change in order to support v6. It's not that there aren't investments in this area, it's just a non-trivial effort.

Source: Worked in GCP networking.

[macintux]

Were they surprised that IPv6 existed? It's not as though this is a new technology, or that the necessity hasn't been obvious since around the time Google was born.

[p1mrx]

It takes longer to climb a hill if you start by digging a hole.