I would argue the current Bitcoin consensus mechanism is "Delegated Proof of Work".
See my quote below from another thread for how this got started:
A common complaint of DPoS is that it can't be decentralized because it has the word "delegated" in the title, yet anyone mining with a pool in PoW is doing the exact same thing. Satoshi made the claim of one CPU, one vote, yet you're delegating your vote to the pool owner in PoW pool mining. Some argue you are not delegating in PoW because you can solo mine. While this statement would be technically correct, the miniscule portion of the Bitcoin userbase able to do so makes it functionally infeasible. It's only a question of what percent of the hash rate is being delegated at any given time.
I would make the argument that for the Bitcoin devs to not be misrepresenting how the system actually functions, one of the following actions would have to be taken:
A) Rename the consensus mechanism to Delegated Proof of Work
B) Implement the Andrew Miller non-outsourcable problem fix in a hard fork
https://bitcointalksearch.org/topic/a-non-outsourceable-puzzle-to-prevent-hosted-mining-and-mining-pools-309073The argument against my statement, is that as long as you can opt out of delegation, even only one person out of six billion choosing to solo mine with a trivial hashrate, then my statement would be false. This argument doesn't make sense because ever since the first pool was created, I can now
always opt out of direct proof of work, and choose to
only delegate my vote. Both choices are represented equally. The Bitcoin protocol does not guard against my action without the Andrew Miller fork.
The other problem with leaving the system as is, is the majority of the community, probably including most Bitcoin devs, claim that PoW is the only known, secure consensus mechanism. Delegation and direct voting (PoW) are represented as equal choices, yet are two completely different things. If you claim that only one person out of six billion can be solo mining with a trivial hash rate, while everyone else is delegating (pool mining) and still be secure, you're endorsing delegation as secure by default. At that point, there would be no reason to use PoW at all over a better engineered delegation system, unless you demand a specific origin of money school of thought until all coins have been mined. After they have been mined, that part is out of the equation.
For the detractors that try to claim this is all semantics, I would say it's the exact opposite. If you incorrectly define what the current system is, and what it's actually doing, it makes it extremely hard to define what type of changes can be done to improve it.