The Cardinals seem to me like an obvious example of how big a difference it makes in the modern NFL to draft the right player at QB. Without a dynamic superstar at QB your team is irrelevant, bound to struggle. With one, you have a chance to do exciting things.
At the same time, it's clear that outright tanking in the NFL doesn't really work. The best QBs are often not taken in the top 10 of the draft. I don't know where that leaves fans of teams without a clear answer at QB. At least in the NBA you can try to get excited about ping pong balls.
Your comment made me do some research on where all the starting QBs in 2020 have been taken. Exactly 16 of the 32 starting QBs were taken in the top 10. Whether they are the top QBs in the league is another story though. Of those 16 the only ones that have won SuperBowls are: Nick Foles (88), Aaron Rodgers (24), Patrick Mahomes (10), Cam Newton (1), Drew Brees (32), Ben Roethlisberger (11), Russell Wilson (75), and Tom Brady (199). Incidentally Tom is the lowest picked starting QB in the league right now. And Murray, Allen, Burrow, Mayfield, Tue, Jones and Darnold have been in the league for less than 4 years. They could still turn into franchise QBs but the jury is still out on them.
That said, it's still probably worth Tanking for Trevor
You make a good point that the evidence does seem to be strong that picking in the top 10 or so of the draft is the best way to get a long term starter at the QB position, even if that guy doesn't become top 5 in the league.
I think my fear is seeing the Pats turn into the Dolphins, Bears, or Browns -- shuffling through QBs endlessly for decades.
I don't know that that is necessarily true because you have to account for all the failures. Teams reach tremendously for QB's so they, by and large, go a lot higher than they should.
2008 - Ryan went 3rd, Flacco 18th. Henne in the 2nd round. 13 drafted overall
2009 - Stafford and Sanchez were the top 10 picks. Josh Freeman went mid 1st. No one else worth mentioning. 11 drafted overall.
2010 - Bradford went 1, Tebow went 25 as the only 1st rounders. Clausen was the only 2nd rounder. Colt McCoy went in the 3rd. Rest of the draft was garbage. 13 QB's overall.
2011 - Cam, Locker and Gabbert were all top ten picks (so just 1 of 3 hitting). Ponder went 12th (another miss). Dalton and Kaepernick were solid 2nd round selections. Tyrod Taylor went in the 6th round. 12 taken overall.
2012 - Luck and RG3 were the first two picks and Tannehill came in at 8th (and look what he turned into like a decade later). Weedon went 22nd and Osweiler was the only 2nd round pick. The 3rd round was fantastic though with Russell Wilson and Nick Foles, and Kirk Cousins coming in the early 4th. 11 taken overall
2013 - No top 10 QB and only EJ Manual went in the 1st. Geno Smith was the only 2nd rounder. 11 QB's taken and seemingly unchallenged as the worst QB draft ever.
2014 - Bortles went 3rd. Manziel 22nd before Bridgewater was the last pick in the 1st round. Carr and Grappolo were both 2nd round picks. 14 QB's drafted overall.
2015 - the first 2 picks were QB's (Winston & Mariotta), the next QB taken was in round 3 (Garrett Grayson who basically didn't play in the league) and there were only 7 taken
2016 - the first 2 picks were again QB's (Goff & Wentz) - Lynch went at the end of the 1st, Hackenberg in the 2nd, Brissett and Kessler in the 3rd, Dak Prescott in the 4th, and a bunch of other players mixed in with 15 total drafted
2017 - the first QB was Trubisky and Mahomes went 10th. Watson 12th. Peterman went in the 5th round. 10 QB's were taken no one else really worth mentioning
2018 - 4 top 10 QB picks - Mayfield, Darnold, Allen, Rosen. Lamar Jackson went at the end of the 1st. The next QB taken was Rudolph in the 3rd. 14 QB's ended being drafted
2019 - Murray and Daniel Jones went in the top 6. Haskins went 15th. Drew Lock in the 2nd, Ryan Finley and Jarrett Stidham in the 4th
You can go back further and see similar patterns. There are a lot of misses at the top of the draft. Sure you get a lot of great players, but the bust rate is high. Even guys that seem ok like Mayfield and Darnold, you wonder if the Browns were better off going in a different direction (either trading the pick or taking Barkley, Ward, Chubb, etc.) and the Jets would have been better off not trading up. The year before Chicago traded up for Trubisky. That obviously was a terrible move. Teams do crazy things for QB's and it quite often back fires.
All that said, Trevor Lawrence is a monster. The best QB prospect since Peyton Manning. He could dominate the league for years. Though they said the same thing about Andrew Luck who walked away after 6 injury riddle seasons without making a Superbowl (and just 1 conference final).