The comment you replied to mentioned that "Large companies ... make billions of dollars handling [databases] for $companies." Central databases have become excuses to erect toll booths that blockchain may eliminate.
Because $company is only one of a number of competitors and none of them is going to let one of them handle the pot.
And because there's distribution but also only a small number of semi-trusted peers, a "blockchain" would be efficient as it wouldn't have to be a proof of work, it would only need to be a signed "public" ledger (public in the sense that all companies can access and add to it). Don't think bitcoin, think a git repo with a bunch of committer signing all their commits.
If you don't trust your business partner, don't do business with them. If there are problems, contracts and courts decide what to do. There is no need for blockchain.
When you have large industries with thousands of peering organizations all over the world, you can't just "trust" -- there is, in fact, no metric for trust and no ability to measure trust. That's why the middlemen exist.
This is especially true in finance, healthcare, and other industries where blockchains are being used.
It's a lot of work, that's why.