Consensus vs. Mediocrity

I had an interesting discussion with a friend a few weeks ago on the subject of consensus.
One insight came out of the discussion is the relationship between consensus and mediocrity. As the group of participants gets bigger and everyone tries to reach a consensus, then the result will be mediocre.
I am not a statistician nor mathematician. However, I think that is logical. Imagine if everyone in the group is aiming to reach a consensus, there will be a convergence of opinions moving toward the average. In addition, as more people join the group with the same behavior, the group average will move closer to the average of the population (mediocrity).