I hope there is a public postmortem that explains this. I have Cloud SQL instances with high availability enabled that have been down for over 5 hours with no workaround, when (according to docs) they should have failed over to the unaffected zones within minutes.

GKE user in that region, we are down.

I think it's deceptive to say it's a single zone. We have VMs across three zones, but anything stateful on zone a is stranded, we can't get the volumes back. It's not just that the zone is down, it's that services are not easy to fail out of the impacted zone or move that's the problem.

Kind on implies regional isn't good enough to secure high availability. You need multi regional deployments. Good luck with that when the bill comes due.