Since 2010 there have been 84 QBs drafted. Of these Sam Bradford, Cam Newton, Andy Dalton, Colin Kaepernick, Andrew Luck, Ryan Tannehill, Kirk Cousins, Blake Bortles, Derek Carr, Teddy Bridgewater, Jameis Winston, Marcus Mariota, Trevor Siemian, Carson Wentz, Nick Foles, Brock Osweiler, Tyrod Taylor, Mike Glennon, Russell Wilson, Dak Prescott have really done anything worth mentioning in the NFL. Of these, you can say Newton has had some success since he did go to a SB although that seem to be a career year for him as some of his others were pedestrian at best. Dalton has been steady but nothing spectacular, Bortles has started a good number of games but hasn't been consistent, and Luck has been above average but doesn't have a good team around him. Prescott had a great rookie year but we have seen others have a bright year or two then fall like a shooting star. The rest have been average starters to competent and somewhat inconsistent starters. Of all these you could say Luck is a legit franchise QB and Newton is borderline. Carr has shown the potential to be one and I think it's too early to anoint Prescott as one. Remember RGIII first year was a quite a success. Dalton has been competent but not a top tier QB. The rest all have warts. Now looking at this you have one legit franchise QB taken in the last 7 years. What are the odds you are going to find one this year? One out of 84 is a .011% chance. It seems that as the college game has moved away from any type of pro style offense the odds of getting a QB anywhere near the level of say a Brady or Rodgers or even a Rivers is pretty slim. Sorry I almost forgot about Wilson. Wilson is near franchise or is franchise level. So even if we make Wilson a franchise QB the odds only increase to .023% chance. Thinking you are going to find that next franchise QB is pretty non existent. I think the best a team could hope for is to find a competent QB who fits into your offense and hope you can develop both physically and mentally as well as break poor habits and one that can be some sort of leader who the team believes in. I personally think you need to select one that you believe has the mental capacity to learn the pro game and learn to go through his reads and move in the pocket and not one that will simply take off anytime there is pressure or the first read is not open.
There were 19 first round selections since 2010. Of those Bradford, Newton, Luck, Tannehill, Bortles, Mariota, Winston, RGIII and Bridgewater have been legitimate starters (by starters I mean played in the majority of their team's games for two seasons or more) since their selection. Wentz started all 16 games for the Eagles. Nine, (Taylor, Kaepernick, Dalton, Cousins, Foles, Wilson, Carr, Siemian, and Prescott) who were selected in the second round or later have also been starters for their teams under the same criteria again with Prescott and Siemian being a 16 games starter for their teams. Doesn't seem like there is any advantage to reaching for a QB in round one is going to net you a starter that will be any better than one in a later round.