Yes, you need to draft one. Two great examples. But AZ failed twice, Cleveland, NY jets and giants, Chicago seemingly twice, panthers, Denver, Philly once, Rams so they traded, Tennessee, raiders, Detroit, Tampa all failed. So yes you have to take a chance. No doubt. But 95% most probably fail. And you gave example of two elite QBs one of them drafted as the top pick.
So the lower in the round you are, the lesser the chance of success. And to get a potentially good one , you need top 10 pick, which means you have to suck really bad.
So who is the can't miss prospect this year?
In the meantime teams have gone to and won superbowls with less than perfect QBs.
Dak is not elite. He is not as bad as the Dak haters claim nor as good as some of his ardent fans claim
The biggest biggest biggest challenge is Jerry Jones. He of the mindset that wanted to pick Manziel and trade up to get lynch. Do you trust him finding an elite QB?