In the Fediverse, what is the solution to instances or servers going missing?

To elaborate: The problem with commercial aggregators like Reddit, Twitter/X, Facebook, etc. is enshitification, for one reason or another. Of course, Lemmy, etc. on the Fediverse is the alternative solution, seemingly. But let's say that the hardware for a large Lemmy instance just disappears. What happens to all of the posts? Yes, old posts will still be available for a while on other instances. But, seemingly, there won't be any more updates. How is this addressed?

Moderators would of course be interested in continuing but they may not have the skills and resources to set up the hardware.

Instances/servers can disappear for many reasons: retirement, illness, confiscation, war, bungee jumping or parachuting accident, ... the list goes on.