So what you're saying is that the Cowboys were able to put a talented roster around Romo despite his massive franchise contract. You may be explaining how they did so...but that is all you are doing. So we agree: giving Dak Prescott is massive franchise contract...does NOT prohibit the Dallas Cowboys from putting a talented roster around Dak.
The Cowboys need to simply continue to manage the cap...and draft well. By the way, the Cowboys would need to manage the cap and draft well even without Dak's potential contract. And just because Dak doesn't get a franchise contract doesn't guarantee that Dallas will manage the cap or draft well either. The Browns, Jets, Cardinals, Bucs, Dolphins, and Jaguars are a testament to that as they have all recently had highly drafted rookie QBs on contracts and have almost nothing to show for it.
I have never rated Baker Mayfield.
Josh Rosen has been disappointing so far but he did play behind a truly horrific offensive line at the Cards.
Winston has been feast or famine but again, the Bucs don't have a great O Line although he has some quality weapons to throw the ball to. Generally had a poor running game though.
Dolphins have had a truly awful offensive line.
Jaguars haven't had a great offensive line either.
Sam Darnold has shown promise playing behind a truly awful offensive line and very few weapons.
The common theme above is regardless of how impressive/disappointing the rookie quarterbacks have been, they have not played behind good offensive lines with the exception of Baker Mayfield who has been overrated thus far.
I would be interested to see how the likes of Darnold and Winston would fare behind strong offensive lines.
Your post just reinforces my view that I cannot see Prescott refusing to sign a franchise tag unless he is only motivated by money. He has had extremely favourable conditions for a quarterback compared with those teams mentioned above (except the Browns last season).
He would be in a for a real shock if he played on an offense like the Jets had last season.