The impact of a us-east-1 Route 53 outage can be global, though. To quote Amazon:
Several AWS services create resources that provide a resource-specific DNS name(s). For example, when you provision an Elastic Load Balancer (ELB), the service creates public DNS records and health checks in Route 53 for the ELB. This relies on the Route 53 control plane in us-east-1. Other services that you use might also need to provision an ELB, create public Route 53 DNS records, or create Route 53 health checks as part of their control plane workflows. For example, provisioning an Amazon API Gateway REST API resource, Amazon ELB load balancer, or an Amazon OpenSearch Service domain all result in creating DNS records in Route 53. The following is a list of services whose control plane depends on the Route 53 control plane in us-east-1 to create, update, or delete DNS records, hosted zones, and/or create Route 53 health checks. <long list of Amazon services follows>