We've seen nearly every other franchise lap the Cowboys over the last 28 years multiple times, and yet we still have a subsection of the fandom that is too terrified to ever try what these other, more successful franchises do.
First, not every other team has rebuild and been to a conference championship game.
There are lots of teams that have tried to rebuild and failed. The Bears, Giants, Commanders, Panthers, Jets (who have drafted more !Bs than any other team in the league since 2000), etc. The OP picked out 2 teams that had success.
And this ignores that fact Dallas has been through this as well, after Aikman retired.
Tony Romo was the starting QB in Dallas for 10 years. In 2015 he was injured but he began the season as the starting QB. Romo didn't do any more than Dak has done. Romo was the QB when Dallas went 13-3,had a bye and home field, and lost to the wild card Giants when they failed to score more than 17 points. I don't recall Cowboys fans talking about blowing up the franchise and starting over with a new QB then. I don't recall as much chronic complaining about Romo. In fact, to this day people still defend Romo claiming he was better than Dak even though he didn;t do any more than Dak.. But let's ignore the Romo years because that is evidence the problem is not Dak, but something else.
I don't know how anyone could watch the two games yesterday and come away thinking Dak is the problem. Purdy was awful again for most of the game. He threw a big INT and was way off on a number of his passes. His QB rating was 89. Goff's was 88.8. Dak's QB rating against GB was higher than both of them at 89.8. Lamar Jackson's QB rating was 75.5. Sure Purdy brought his team back to win, but Purdy didn't suffer the futility of watching his defense give up easy TDs after he took his offense down the field.
Goff, who many claimed was better than Dak last week after the Lions beat the overrated Bucs, looked awful in teh 2nd half too. A total collapse. If Dak played like either of these two QB, he would be ridiculed mercilessly by Cowboys fans. They would say the Cowboys won despite Dak, or if they lost it would be his fault.
Two things stood out to me in yesterday's games. 1, winning teams have the heart of champions. They step up when they have to and it is not just 1 man. Who thought the Chiefs would shut down the Ravens yesterday? The ravens were the biggest, toughest, runningest, team in the league. They were the favorites. KC man-handled them all over the field. The heart of a champion made them better.
The second thing is, the teams that make the fewest mistakes win. It is not rocket science. The Ravens committed some really stupid penalties that hurt them. Zay Flowers made 3 huge mistakes in a space of about 5 minutes, including fumbling the football 6 inches from the goal line giving the Chiefs a touch back. Cardinal rule, don't reach the football out like that stretching for the goal line in traffic - for exactly that reason. The taunting penalty was even dumber. And Kyle Van Noy was baited into a 15 yard penalty by Taylor Swift's boyfriend. Dumb. Those are the kind of mistakes winning teams avoid. Dallas makes them all the time. Not Dak's fault.
Winning teams have big hearts, and they are disciplined, even under the pressure of big games. Even if Dak had the biggest strongest heart in the league, if the rest of the team plays dumb, and doesn't get up for the big games, Dak still loses.