Dumb question time: Aren't 95% of these use cases more easily implemented with a single central source of truth, possibly with distributed read-only repl

Dumb question time: Aren't 95% of these use cases more easily implemented with a single central source of truth, possibly with distributed read-only replicas? Absolutely. The tech press loves its fancy new craziness. Good engineering should be exciting enough (if they want to write about something cool they could write about immutable databases like Datomic), but no . . . _blockchain_!