that's called enforcement of the law, that can rely on force, if necessary.
a blockchain has the same value of paper (on paper) but it can be shut down by cutting electricity and, most of all, has no way to enforce what's stored on it.
Because no trusted party is willing to make the effort, there is no way a bunch of individuals are going to come together and declare war (to whom?) to make it stick.
This but unironically.
The blockchain can't inspect a house before sale. The blockchain can't test the water quality outside of a factory upstream from your town.
However I’m not sure what you mean to signify with your paper vs stone tablet comparison. Unlike blockchains, paper doesn’t claim to do anything magical compared to stone tablets - it’s still just a medium of storing written text.
How many blockchain hype people are explicitly promoting wars for independence, though?
Otherwise known as working State with an army, a navy, nukes, and democracy (for stability), or some semblance thereof, and all the other stuff that keeps it humming along for 200+ years despite internal turmoil, foreign attacks, and all that. And rich enough to keep its economy humming too, and its coffers flush with cash and other reserves.
That's what makes a stable currency; not "fiat" or "paper stacks".