I'm always told that one of the main benefits of a blockchain is that it enforces trust, or something to that extent. But enforcing trust in databases is not an open problem. Databases successfully store data. Therefore blockchains seem like a 'solution' to a problem that doesn't exist.
if we are talking public blockchains,
Immutablity, decentralized trust and censorship resistance<p>Private blockchains can be anything the owner wants them to be.