If your goal is to avoid downtime in case of nuclear war, you could use a managed distributed database solution from a cloud provider.

Also, attacks against 'on-prem' services still scale, in the sense that an exploit against a service's code can be used on any number of independent deployments of that code. The solution to that is to actively avoid monoculture. [0]

[0] https://indieweb.org/monoculture