Here is a video displaying how asset markets are efficient. Its created by the market makers. Without market makers all markets will be non-efficient and would lack liquidity. The lack of liquidity occurs because there would be no meeting of the minds between buyers and sellers. This is why they (market makers) CREATE the market. They are the conductors. Its their job to create a efficient and orderly market. The individual on this video is such one. They play a valuable role. I would suspect that in the future AI will be the conductors of markets.
Have a listen.