It's a lot easier to instruct a rack of servers, or even a set of (centrally managed) desktop machines, to wipe itself than it is to physically destroy it, let alone the equivalent amount of information on paper.
Moreover, assuming encryption is in place, destroying the keys without touching the actual data is generally sufficient.
You will probably want to wipe the data then destroy the hardware as defense in depth, but in a dire emergency, taking the one thermite charge to the central key management server and its backup and cutting the power feed to the rest of the infrastructure is going to be good enough.
With human readable information on paper, you simply have no other option than physical destruction, which is an extremely slow and labor-intensive and manual process. Even with preparation, you can't really accelerate it much, whereas with digital information prepared for the possibility of needing emergency destruction, it's a matter of pushing a button and the data is gone less than a second later.
The flipside of that is that the worst crimes of a future surveillance state will likely stay hidden even after it gets toppled, unlike the East German Stasi that failed to destroy many of its documents in time.