That's true. It's just that it is impossible to predict which QB in the draft is going to have a Hall of Fame career. Sometimes people predict that and are basically right (Luck - if the Colts had a decent OL to protect him).
But more often even the top 2 picks are good QBs, but not Hall of Fame worthy (Jared Goff and Carson Wentz so far, along with Pat Mahomes (#10), DeShaun Watson (#12), and other young QBs who have yet to prove themselves in the playoffs).
But, lots of times the QBs taken in the top 5 are flat disappointments - (Jameis Winston, Marcus Mariota, Blake Bortles, RGIII, Jake Locker, Mark Sanchez).