These kinds of outages continue to happen and continue to impact 50+% of the internet, yes, they know they have that power, but they dont treat changes as such, so no, they arent aware. Awareness would imply more care in operations like code changes and deployments.

Outages happen, code changes occur; but you can do a lot to prevent these things on a large scale, and they simply dont.

Where is the A/B deployment, preventing a full outage? What about internally, where was the validation before the change, was the testing run against a prodlike environment or something that once resembled prod but hasnt forever?

They could absolutely mitigate impacting the entire global infra in multiple ways, and havent, despite their many outages.