Because separation of the record from the record keeper means the system will be endowed with new attributes such as accuracy, verification. distribution, longevity etc that result in a more robust and valuable system.

Imagine you run a fast food franchise with 10 restaurants, each keeping their inventories in a local database, how do you coordinate global restocking? Manual reconciliation across each database. Ok move to the cloud. Now you have a global picture where state is adjusting in closer to real time and reconciliation is an inherent property of they system rather than a process implementation operationally. Well as I have described elsewhere in this thread. A lot of financial transactions are managed in an equivalent process of local databases with manual reconciliation.

I am oversimplifying because there are a number of road blocks that prevent a solution like “implementing a cloud database” and also conflating what happens within a company (using the franchise analogy) rather than a market (where every single franchise had a common inventory and ordering system not tied to a third party supplier). By my point is that a block chain ledger would solve many of these problems without users even being fully aware of the problem in the first place.