It’s not that simple. The bit AWS doesn’t talk much about publicly (but will privately if you really push them) is that there’s core dependencies behind the scenes on us-east-1 for running AWS itself. When us-east-1 goes down the blast radius has often impacted things running in other regions.

It impacts AWS internally too. For example rather ironically it looks like the outage took out AWS’s support systems so folks couldn’t contact support to get help.

Unfortunately it’s not as simple as just deploying in multiple regions with some failover load balancing.