Too Long; Didn't Read
Consensus is a dynamic way of reaching an agreement in a group. While voting just settles for a majority rule without any thought for the feelings and well-being of the minority, a consensus, on the other hand, makes sure that an agreement is reached which could benefit the entire group as a whole. The main drawback of POW is an extremely inefficient process because of the sheer amount of power and energy that it eats up. There will only be no miners in the Proof of Stake.