And Prescott, Wilson, Winston, Carr, Stafford, and Flacco did not.
But when Tannehill in '15 had nothing to work with, he gets blamed while the above usually get a pass, although Winston has sucked almost throughout,
Stafford has been largely a disappointment, Wilson, like Tannehill has demonstrated that he can't work miracles, Carr is overrated and Flacco is Flacco. Prescott revealed himself, without Zeke to be the 4th round QB in which he was selected.
So to your point that not the best QBs make the playoffs, you're right, and there are reasons why beyond their own contributions.