You can get snapshots and live migrations working on-prem. The cloud isn't magic, it's just servers with hypervisors and software running on top of them. You can run that same software.

Also, with something like Hetzner you would not be going in and physically doing anything. You also just tick a box for a RAM upgrade, and then migrate over or do active/passive switch.

The cloud does have advantages, mostly in how "easy" it is to do some specific workflows, but per-compute it's at least 10x the cost. Some will argue it's less than that, but they forget to factor in just how slow virtual disks and CPU are. Cloud only makes sense for very small businesses, in which the operational cost of colocation or on-prem hosting is too expensive.