:)
No. The cloud (AWS, GCE, Azure etc) is not "just" like your own server.
Just consider some basic details - you pay someone else to worry about things like power outages, disk failures, network issues, other hardware failures, and so on.
But... that "point" is trivial.
Did anyone ever claim that cloud servers are made of magic pixie dust? No.
The real "point" is that, cloud = hardware + service, with service > 0.
As the OP describes, GitLab tries to do their own service (because service is expensive... it is), and they find out, the hard way, that the "service" part is not easy at all.
Amazon & Microsoft & Google run millions of servers each, so they can afford to hire really good people, and establish really good procedures, and so on.
That, I think, is a better point
Something like this is not a mere oversight on the part of technical leadership; it's either negligence or incompetence. Whoever is responsible for GitLab's server infrastructure should be having very serious thoughts right now.