Not stirring the pot for the sake of stirring, but legitimately asking...
If you consider the majority of the best pure pocket passers who are champions are long in the tooth:
(P. Manning 39 his final season), Brady 40, Brees 38, Rivers & E. Manning 36, Big Ben 35, Rodgers 34, [let's call this group A]
...And the apparent dearth of up-and-coming pure pocket passers to replace them:
Goff 23, Wentz 25, ...whom else do you want to place on that list [let's call this Group C]?
Would you then consider that any of the handful above-average pocket passer QBs in the in-between "age gap": Alex Smith 33, Matt Ryan 32, Stafford & maybe Cousins both 29, Luck 28 [let's call this Group B] have anywhere near the chance of success that the Group A QBs have had? (I'd argue Stafford has the best shot after Luck, assuming Luck can come back from injury.) Smith, Ryan, Stafford, Luck all Rd1, #1-3.
Let's further assume the dual-threat QBs will have shorter careers (Wilson, Newton, Taylor, Prescott, etc.), so it might actually make sense to avoid drafting them from a depreciation standpoint / preservation of value.
Then to me, it boils down to 3 scenarios:
1. Trade up to draft the can't-miss franchise QB, and have him turn out to actually be that QB, and be on a team good enough to do it. What team would trade with BUF to give the Bills that chance? I just don't see it.
2. Trade up to draft the can't-miss franchise QB, and have him "languish" on a team which can't get over the hump.
3. Draft QB when the player falls to you and develop and hope you get the next Big Ben, Rogers, Brady, (Wilson).
If only it were that easy, each and every year, why don't all teams do it?