I didn't say Tony's play last season was specifically better, for the record. Only that Tony's a better player than Dak is. As far as those games go, though, NY, PHI, CAR, and MIA are not what I'd consider lesser competition to what Dak's faced this year. Of those four games, you had the miracle comeback in week 1 that was all on Tony, he got hurt in week 2 v. PHI, came back after many weeks off v. MIA and didn't play great, and then was rolled in CAR. Not Tony's best stretch of games, to be sure, but pretty obviously due to injury and time off.
That said, he's a better QB than Dak is over his most recent stretch of full games in the lineup, against better quality competition. He sees the field better, reads the defenses better, makes more big plays, and is just a smarter QB right now. And this team believes in Tony every bit as much as they believe in Dak Prescott.
Dak's got all the potential in the world, and he's on a trajectory to be a great QB in his own right. When Tony comes back after next week, you watch. You're going to hear him say exactly what I'm saying now. There's a lot he can still learn about NFL defenses, and Tony's a great guy to teach him. They're both going to respect each other, both going to be good teammates, and both are going to understand the reality of the situation is that we've got two capable QBs right now for the first time in a long time. The writing is on the wall for Tony, but Dak can afford to be patient, and he can use the time to get better. He can't get where he wants to get by staging a coup in the locker room. Not with this team and this coaching staff. So he'll take a year and change to prepare and be ready when the next opportunity presents itself. Next time up, I think the gig is his for the long haul.