This stuff may look new and revolutionary to some, but if you've been here long enough you've already seen that stuff go through the hype cycle[1] and it has NOT emerged, at least so far, at the end of that curve looking good.

I am currently working on some stuff where blockchains are actually a potential solution (very related to public key cryptography, by the way), but the problems with it as a solution to anything except digital casinos are so numerous and the scams so prevalent in this space that it's next to impossible to come up with genuinely useful applications and services that rely on it. That's the reason why usages of this technology are currently extremely limited, not because there's some sort of conspiracy to stop it from succeeding!

[1] https://en.wikipedia.org/wiki/Gartner_hype_cycle