Places nobody's ever heard of like "Ohio" or "Oregon"?
Yeah, I'm not worried about being targeted in an RCA and pointedly asked why I chose a region with way better uptime than `us-tirefire-1`.
What _is_ worth considering is whether your more carefully considered region will perform better during an actual outage where some critical AWS resource goes down in Virginia, taking my region with it anyway.
IAM and Route53 have dependencies on us-east-1.
AWS Organizations/Account management is us-east-1.
And if you want a CDN with a custom hostname and want TLS…you have to use us-east-1.
The Route53 control plane is in us-east-1, with an optional temporary auto-failover to us-west-2 during outages. The data plane for public zones is globally distributed and highly resilient, with a 100% SLA. It continues to serve DNS records during regular control plane outages in us-east-1, but access to make changes is lost during outages.
CloudFront CDN has a similar setup. The SSL certificate and key have to be hosted in us-east-1 for control plane operations but once deployed, the public data plane is globally or regionally dispersed. There is no auto failover for the cert dependency yet. The SLA is only three 9s. Also depends on Route53.
The elephant in the room for hyperscalers is the potential for rogue employees or a cyber attack on a control plane. Considering the high stakes and economic criticality of these platforms, both are inevitable and both have likely already happened.
IIRC, some AWS services are solely deployed on and/or entirely dependent on us-east-1. I don't recall which ones, but I very distinctly remember this coming up once.