Is this just for dilution of responsibility? If a central company is responsible for these transactions, then they are responsible for the transactions, which means there are all kinds of legal constraints and repercussions. But if it's a blockchain, then all of the nodes in the network are responsible.

So in this case, "this business is incentivized to be honest" might be the precise "problem" this is meant to solve.

Or further, that you need to interact with a business at all. Visa does a good job intermediating many classes of payment. But I am limited in what kind of applications I can build on top of that (tied directly into the payment)