I have said this for years, and in most cases regarding free agents, it plays out.
Circumstances change from team to team. Just because a guy plays for Team X and did well, does not translate to him coming to this team and replicating that success. Not all circumstances are alike.
This is a team sport predicated on scheme and coaching. The players surrounding said player may have offered him the opportunity to shine. The scheme or coaching could have added to this, or been the lynch pin to make this player be attractive in free agency.
The assumption a substitute could arrive and perform at the level they did with their previous team, thus supplanting the player here doesn't bear fruit at enough frequency to suggest all things are equal.
It is said here time and again free agency does not bring in the quality versus cost in most cases. There are exceptions.
I find it both business as usual when dealing with a player who will be paid a great deal, to find people coming out of the woodwork to hail players for other teams who can easily step in and be better than the player Dallas has now, and a bit hilarious because the same people advocating for these changes at other times of the year bemoan free agency.
Rookie OC and Garrett is a cocktail for 8-8. I see people suggesting let Dak walk and have Mike find his guy. I wonder if any of these folks can point to any factual information which reveals MM doesn't want Dak, nor thinks Dak can get the team where it wants to go?
Personal opinion about Dak foster so many of these threads filled with speculation and no real substance.
New coach, new scheme. Maybe letting the team ferret out this issue would be better served than maybe 300 threads about Dak, Jerry, the contract, Dak's value, his replacement, and the rest of this hand wringing being played out here for the last year.