Of course they do and i'm sure they did with all those other teams too. But those teams found a way to get it done. Why can't ours? I gave you my answer, what's yours. Cowboys want a 5th year, Dak was asking for 45m in that 5th season, do you think 5 years from now that one extra year at that price is the hold up to the deal? If the Cowboys truly want Dak that would not hold up the deal
Dak is playing on the tag this season (at least it looks that way) So does he ask for a 3 year deal next season to keep things at 4 years total? and if the Cowboys offerred him a 4 year deal next season would he take that or turn it down because it just like signing a 5 year deal this year
I don't recall any of those other teams and QB's claiming the player was holding out for a shorter term, or that the team was pushing a 5 year term and was unwilling to bend. Besides, they all got 4 year terms, so Dak asking for 4 years isn't really asking for more than they got.
The difference is more on the team side because since the Cowboys didn't negotiate an extension while the rookie contract was still in place they don't have more time to spread the cap hit over like the Eagles and Rams. My guess is if the Cowboys had made a 4 year extension offer last year in the same range as the Eagles and Rams did, Dak would have got his money, and the Cowboys would have an extra year to spread the cap hit over.
As for how Dak would view things after playing on the tag a year, none of us can say for sure, but that's not really relevant to the negotiation to get him signed today. If I had to guess I would think 4 years would still be okay for him, but the 4 years would be at 2021 market prices rather than 2020.
As for the Cowboys not holding up a deal if they truly wanted Dak, my counter to that would be twofold. First, the Cowboys negotiated hard with Emmitt in 1993, even to the point that Emmitt missed the first two games of the season, and it would be hard to claim the Cowboys didn't truly want him. The second would be that it doesn't seem realistic to think the Cowboys would have stuck so long to these negotiations, or be pushing for a 5th year, if they didn't truly want Dak.