Almost nothing is a unique solution to a set of problems. Just because the problems that distributed ledger technologies address can be solved in a different way doesn't mean that to do so is the right business decision.
Blockchains in particular carry a business penalty for a few reasons. One is that they're novel. As Dan McKinley says, we should "choose boring technology" [1] unless we have a strong incentive not to. Blockchain expertise, to the extent that it exists, is bid up in the marketplace, giving another excellent reason to pick something else. A third is that the vigorous blockchain hype has created a fair bit of blockchain skepticism in reaction. I know people looking for work that won't even talk to blockchain companies. And then we have questions about security, efficiency, reliability, and all the other operational concerns that one mainly learns through hard lessons (hopefully other people's hard lessons written up for the rest of us to read).
Or you can have a "private blockchain", which defeats the purpose entirely.
As far as I can tell, they provide inferior guarantees AND performance to existing methodologies and algorithms.
Digital signatures have been a thing for ages.