While there appears to be some us-east-1 SPoF for Route 53 updates (as shown recently), the actual health checks themselves occur in up to 8 different regions [1] with an 18%[2] agreement of failure required to initiate a failover.

AWS has very good isolation between regions and, while it relies on us-east-1 for control plane updates to Route 53, health checks and failovers are data plane operations[3] and aren't affected by a us-east-1 outage.

Relying on a single provider always seems like a risk, but the increased complexity of designing systems for multi-cloud will usually result in an increased risk of failure, not a decrease.

1. us-east-1, us-west-1, us-west-2, eu-west-1, ap-southeast-1, ap-southeast-2, ap-northeast-1 and sa-east-1 which defaults to all of them.

2. https://docs.aws.amazon.com/Route53/latest/DeveloperGuide/dn...

3. https://aws.amazon.com/blogs/networking-and-content-delivery...