That's more "the experts had a (wrong) opinion on something" than "the experts overlooked something obvious". They didn't overlook it, they thought about it and

That's more "the experts had a (wrong) opinion on something" than "the experts overlooked something obvious". They didn't overlook it, they thought about it and came to a conclusion. And if by "many years ago" you refer to a period where software deployment was mostly offline and through physical media, then it was indeed painful and risky (and therefore expensive). The experts weren't wrong back then.