Append-only, cryptographically verified, distributed databases are a good idea with some useful applications, and I'm sure they'll spread as tech infrastructure just like e.g. stream processing has in the last few years. But that seems barely related to the whole crypto phenomenon which inherently relies on destructive proof-of-work (maybe proof-of-stake will turn out to work at scale but I'm dubious) which in turn requires everything to have financial value and be pumped and presumably eventually dumped.