Consider the track record of first round QBs taken over the last ~20 years (with the jury still being out on the new QBs after 2017). It's a pretty unimpressive success ratio:
2016:
1. Jared Goff, California, Rams
2. Carson Wentz, North Dakota State, Eagles
26. Paxton Lynch, Memphis, Broncos - BUST
2015:
1. Jameis Winston, Florida State, Buccaneers BUST
2. Marcus Mariota, Oregon, Titans Borderline
2014:
3. Blake Bortles, Central Florida, Jaguars BUST
22. Johnny Manziel, Texas A&M, Browns BUST
32. Teddy Bridgewater, Louisville, Vikings BUST
2013:
16. EJ Manuel, Florida State, Bills BUST
2012:
1. Andrew Luck, Stanford, Colts
2. Robert Griffin III, Baylor, Redskins BUST
8. Ryan Tannehill, Texas A&M, Dolphins BUST
22. Brandon Weeden, Oklahoma State, Browns BUST
2011:
1. Cam Newton, Auburn, Panthers
8. Jake Locker, Washington, Titans BUST
10. Blaine Gabbert, Missouri, Jaguars BUST
12. Christian Ponder, Florida State, Vikings BUST
2010:
1. Sam Bradford, Oklahoma, Rams Borderline
25. Tim Tebow, Florida, Broncos BUST
2009:
1. Matthew Stafford, Georgia, Lions
5. Mark Sanchez, USC, Jets BUST
17. Josh Freeman, Kansas State, Buccaneers BUST
2008:
3. Matt Ryan, Boston College, Falcons
18. Joe Flacco, Delaware, Ravens
2007:
1. JaMarcus Russell, LSU, Raiders BUST
22. Brady Quinn, Notre Dame, Browns BUST
2006:
3. Vince Young, Texas, Titans BUST
10. Matt Leinart, USC, Cardinals BUST
11. Jay Cutler, Vanderbilt, Broncos Borderline
2005:
1. Alex Smith, Utah, 49ers Borderline
24. Aaron Rodgers, Cal, Packers
25. Jason Campbell, Auburn, Redskins BUST
2004:
1. Eli Manning, Mississippi, Chargers
4. Philip Rivers, North Carolina State, Giants
11. Ben Roethlisberger, Miami (Ohio), Steelers
22. J.P. Losman, Tulane, Bills BUST
2003:
1. Carson Palmer, USC, Bengals
7. Byron Leftwich, Marshall, Jaguars BUST
19. Kyle Boller, Cal, Ravens BUST
22. Rex Grossman, Florida, Bears Borderline
2002:
1. David Carr, Fresno State, Texans BUST
3. Joey Harrington, Oregon, Lions BUST
32. Patrick Ramsey, Tulane, Redskins BUST
2001:
1. Michael Vick, Virginia Tech, Falcons
2000:
18. Chad Pennington, Marshall, Jets
Albeit, this is a subjective analysis - but by my estimation, that's a BUST or borderline BUST status of roughly 7 in 10 first-round QBs taken. Also, 26 of those QBs were top 10 picks, 16 of whom were busts or borderline busts.
It's not encouraging math. More than 60% of QBs taken in the top 10 have either outright sucked, or have been merely average at best. Even if we have a terrible season and would've been in a position to draft Ben's heir apparent with a top 10 pick, it's more likely than not - given historical precedent that this QB would fail.
This makes me feel that much better about the Minkah Fitzpatrick trade.