Yes, it's the least reliable. Thanks for summarizing the data here to illustrate the issue.

It's often seen as the "standard" or "default" region to use when spinning up new US-based AWS services, is the oldest AWS center, has the most interconnected systems, and likely has the highest average load.

It makes sense that us-east-1 has reliability problems, but I wish Amazon was a little more upfront about some of the risks when choosing that zone.