Consortium blockchains are any attempted (and the impossibility of a perfect) solution to the Byzantine Generals Problem (aka Byzantine agreement) which has bounded synchronous finality of irreversibility5; and thus mathematically must have a bounded+permissioned delegate set subject to a ¹/₃ liveness threshold with ²/₃ safety margin.
If you are referring to Bitshares/Steem as consortium blockchains, then I would say that delegates are a solution to scalability, high performance and minimal cost of sustaining the network and processing transactions. Or are you trying to say that it is actually an attempt to achieve finality faster?
I find this post very technical, but I think I understand something of what you mean. What do you think of Steems runner-up-witnesses?
RE: “Consortium blockchains” (e.g. DPoS & Tendermint) can’t Internet scale