> but the concept of an immutable, append only, tamper-proof ledger underpinning it is a very useful one

Which is why blockchains have become such a ubiquitous technology. They're literally everywhere. Can't swing a cat without hitting a blockchain nowadays.

You have responded to the wrong comment. I have presented a case that concerns ledger databases, not the blockchains. If one doesn't understand the difference between the two, it is probably a good idea to refrain from chiming in.