There is information to suggest Bitcoin is centralised.
It is being challenged by BCash in an effort to evolve the
blockchain.
The BCash fork is to help Bitcoin survive the future,
a future of very fast blockchains.
There is another point of view which is important to consider.
Any Proof of Work blockchain has the potential to be centralised.
If someone has enough money to purchase a bunch of
mining equipment they can become a very large power
on the mining scene.
They are doing more work, so they have more power.
This is why DPOS is the perfect mining format. No person can
gain the power of the chain, it is incorruptible.
I think you are hinting at a very important aspect of the cryptocurrency space; namely, with consensus algorithm is best with blockchains? It is quite obvious that PoW is very wasteful, but certainly a reliable form for securing the network. POS and DPOS alleviate the waste for consumption of electricity. It would be interesting to see if these systems can be co-opted by bad actors or oligopolies. Seems the steem is doing well so far. I believe there should be more research into alternative systems to consensus so that actual experimentation in real-world networks can determine winner(s).