Triple-entry accounting, basically. There was an article on here a few months ago that went into depth on the issue.

Double-entry accounting made it much harder to cook the books (a record of where money is coming from and a record of where it is going). Blockchains store every transaction within the coin itself and are validated by the entire network as valid transactions.

People promote Bitcoin as anonymous, but it's actually the opposite - every transaction is traceable and open source, even if the accounts are not tied to a person directly.

There are uses for this but I think the unintended consequences remain to be seen. I think of how people were able to be identified by that Netflix ratings datadump a few years ago, so imagine how easy it would be if Bitcoin became a common currency? I am not positive this is possible (I think it is?) but imagine I buy an apple from Whole Foods and pay with Bitcoin. Now I know what account they use and I can go back through the blockchain to see every other transaction they've ever made: bam, now I know all financial data about Whole Foods over Bitcoin including which accounts pay them the most and the datestamps of those transactions.