We have or had alternatives - rackspace, linode, digital ocean, in the past there were many others, self hosting is still an option. But the big three just do i

We have or had alternatives - rackspace, linode, digital ocean, in the past there were many others, self hosting is still an option. But the big three just do it better. The alternatives are doomed to fail. If you use anything other than the big three you risk not just more outages, but your whole provider going out of business overnight. If the companies at the scale you are talking about do not have multi-region and multi service (aws to azure for example) failover that's their fault, and nobody else's.