Are there any services that track uptime for various regions and zones from various providers? It's rare that everything goes down and thus the cloud providers pretend they have almost no downtime.
CloudHarmony used to track this at some level for free, but it looks like you now need to sign-up or pay to get more than 1 month of history?
The last time I looked at it (back when it showed more info for free, IIRC), AWS had the best uptime of the three big cloud providers, with Azure in 2nd and GCP in 3rd.
IIRC, the memorable thing was that, shortly afterwards, the head of Google Cloud made a big announcement that CloudHarmony showed that GCP had the best uptime when CloudHarmony showed that it actually had the worst. Google was calculating this by computing downtime = downtime per region * number of regions, but at the time, Azure had ~30 regions and AWS had ~15 vs. ~5 for Google and if you looked at average region downtime or global outage downtime, Google came out as the worst, not the best.
I can't imagine that being easy or cheap to make given the staggering number of product offerings across even the few big providers and how subtle some outages tend to be.