I'd say you need people with certain skill sets anyways but at a certain scale you have to get specialized people for some service. Database admins, kubernetes admins, network admins. At a small scale that can be one or two people. But if you want 24/7 with a bigger scale you need multiple people for each role. You have to find them, pay them, schedule their absences.

To some management types it looks like a good deal to not deal with that and just let Amazon/Microsoft/Google/etc. deal with finding people to support the service and just pay a bit extra to the infra cost. Then you can only hire cloud infra admins. I don't think it works that way but that is what I have observed.