Draft Picks are a form of capital. This capital is not distributed evenly. As a sense of proportion, the Bengals were given the cash equivalent of say $10 Million dollars for the last draft. The Chiefs were given the equivalent of 2 Million (ratio based on draft value charts). It is difficult to directly compare how teams given different amounts of capital fare against each other. People like to dump on the Patriots drafting. But the Patriots have been drafting nearly last for 20 years.
I think the proper question is not "who is the best drafter" , but rather who makes the most out of the draft capital they are given. The Chiefs have used their draft capital in a way that allowed them to get Mahomes, and to win the most recent Super Bowl. That makes them the unquestioned current leader in the category of who manages their draft capital the best.