But AWS has the concept of availability zones that they equate to a data center. AWS refers to an AZ as an "isolated location". It's becoming clear with the S3

But AWS has the concept of availability zones that they equate to a data center. AWS refers to an AZ as an "isolated location". It's becoming clear with the S3 outages and this outage that isolation is not as robust as expected so now we see more reference to cross-region replication. But unlike cross-AZ services like S3 or DynamoDB, you need to build your own cross-region replication and failover.