I'm not the parent, but I maintain services on both AWS and Azure, and in the last few years, I can definitely say the outages on Azure have been more frequent and more severe. The only AWS outages I recall are S3 and the Dyn DNS issue that brought many other providers down too.
The Dyn DNS outage was easier to explain. Half of the internet is down, it's not just AWS.
Exactly. As an AWS customer, that outage didn't really bother me because it was obvious it impacted many other unrelated services too.
I'd tell them "other providers have inevitable outages, however..."
1. The other providers have a better track record
2. The other providers don't go down globally multiple times a year