I actually thought that digital timestamps would have been a great use-case for blockchains. They are publicly available and auditable. If you're working from hashes, you don't necessarily need to make the raw data public, just the hash. It is a use-case that has an intrinsic value to the data generator and the future auditor (so you could charge something for it). I know there was some work done on this, but I think it lost momentum due to trying to generate crypto as a value storage medium.
The gold bugs really set back that entire field: the quasi-religious pursuit of “trustless” designs made everything more expensive, but so many problems are far more tractable with trusted third parties both for cost and reduced attack potential because institutional/professional reputations are harder to build than getting n% consensus on a cryptocurrency and don’t have the built-in bug bounty problem.
For example, imagine if university libraries ran storage systems based on Merkle trees with PKI signatures and researchers used those for their papers, code, data inventory (maybe not petabytes of data but the hashes of that data), etc. If there were allegations of misconduct you’d be able to see that whole history establishing that when things were changed and by whom, and someone couldn’t fudge the data without multiple compromised/complicit people in a completely different department (a senior figure can pressure a grad student in their field but they have far less leverage over staff at the library), and since you’re not sharing a database with the entire world you have a much easier time scaling with periodic cross checks (e.g. MIT and Caltech could cross-sign each other’s indexes periodically so you could have confidence that nobody had altered the inventory without storing the actual collection).
