> I genuinely don't understand what the blockchain does here that couldn't be implemented by any random database system. A blockchain is...well... a database s

> I genuinely don't understand what the blockchain does here that couldn't be implemented by any random database system. A blockchain is...well... a database system itself! There are many different types of database systems, eg. Relational, Graph, Object orientated, document (eg elastic search) and so on. Generally you want to pick one that fits your problem area well, so picking a random database system would not be a good idea. One of the most important data structures they need is a tree for the Merkle proofs to confirm that the data hasn't been tampered and contract execution happened correctly. Tree structures are notoriously difficult to implement in a relational db for example. (BTW, I'm also skeptical of the hype around 'blockchain' just as before when the 'noSQL' hype came around. You will surely have some devs pick the blockchain as their database system for the wrong reasons, just like back in the day when you had devs pick noSQL because it was cool.)