Doesn't a permissioned blockchain require a trusted central authority to manage the permissions? How is it better than having that central authority manage the database?
You have, say, 50 entities that are part of the cabal, not all of whose interests are aligned (this is the important bit, you want a diversity of interests), and you need a 2/3 vote to add a new one.
Could you give some examples of current commercial relationships that let, say, 50 entities have a binding majority vote? I agree it's in theory possible, but I've never heard of such a thing.