> You need that RAID card which is not available anywhere around you.

If you're small enough to not be able to justify spares, then rent servers instead. It's still cheaper than the big cloud providers.

> You need to visit your Data Center, but you suddenly have issues with security and you need to arrange all that stuff.

You rarely do. Anywhere beyond the cheapest third-rate colo provider provides "remote hands" services.

Even when managing several racks worth of hardware, I'd go into the colo facilities a couple of times a year at most.

> and they have spare parts and they have personnel 24/7

Even tiny colo-providers still have personnel 24/7, and you can buy fractional devops services for small retainers from any number of providers (like me).