if all 60 are working together sure, but if it's a handful of devs working with each other, you can pull directly from each others repository.
PITB, yes. But you can still get work done.
PITB, yes. But you can still get work done.
Plus you are forgetting that lot of automated jobs get triggered on github changes. Many shops kick off all kinds of tests, deployments, and other things based on changes to the github repo.
My point was simply that you can still be productive when github goes down, if you want to be.
I don't think you're "wrong" for the developer use case, but the reality is that it can bring large teams to a screeching halt.