[Retric]

Block chains are at best only secured as much as the hash power to generate them. If your spending 1M / year generateing a block chain it takes about that much hash power to break it.

This creates a vast overhead as you can't secure a billion+ dollar market without massive and continuous investments.

[woah]

You're wrong. Most enterprise blockchains use BFT algorithms or even round-robin instead of mining. What they are after is a highly auditable shared computing environment.

[Retric]

You can use things that are not a distributed block chains.

But if you have some trusted party just use a DB.

[sanswork]

The use of PoW isn't what makes a block chain a block chain. The idea is that you don't have a single trusted party you have a collection of them that need to collude to cause harm to spread the required trust.