If you need global HA to the extent that you're worried about global VPC failure modes, you're going to have to spend a lot of effort to squeeze uptime to the max regardless of where you deploy.
Undersea cable failures are probably more likely than a google core networking failure.
In AWS a lot of "global" things are actually just hosted in us-east-1.
On the other hand, when they say something is in us-west-2 they mean it, so if another region has an outage your workloads aren't impacted unless your code is reaching out to that region.
Guessing that's similar on the other clouds.