Mahomes, Lamar, Watson, Wilson and Brees are clearly better than Dak and sit in a tier above him.
With Rodgers and Brady, it depends on how much gas they have in the tank, and my guess is, not much. I wouldn't say that they are better than Dak at this point in their career.
Wentz, Cousins, Stafford, Murray, Ryan - they are Dak's equal at worst, and I think Dak is better than several of them.
You could rank Dak anywhere from 6 to 10 and not hear an argument from me. He is clearly not in the top 5, but if you start saying he's worse than guys like Jared Goff and Jimmy Garappolo, we're going to have words.