Wouldn't it be possible to create fully independent zones with multiple cloud providers, like AWS, GCP, Azure? This is assuming that your workloads don't rely on proprietary services from a given provider.
Yes, and would also protect you from administrative outages like, "AWS shut off our account because we missed the email about our credit card expiring."
(But wouldn't protect you from software/configuration issues if you're running the same stack in every zone.)
