Then it seems like the data being hashed would be serializations of databases rather than sets of transactions. I.e. you would be publishing snapshots of the world rather than agreed-upon changes starting from a pre-agreed on state.

I’ve been curious about this. I’ve thought about it (inspired by event sourcing), but am not familiar with the Blockchain enough to know if it’s feasible from the trust/security side.

At some point you will just be implementing your own half-assed blockchain because you "don't need a blockchain". Why?