I think what he's saying is that over the last 5 games of his rookie year, Baker Mayfield's stats were better than Mills' (115/175 for 65.7% completion, 1483 yards, 10 TDs and 7 INTs for a passer rating around 111 if my math is right). He played better, at least technically.
Cleveland followed the logic of thinking they had their QB and built a really good team around him, but it hasn't amounted to anything because he's still not The Guy. So now they're mortgaging their future away to try to get that final piece at QB.
I might be getting the conclusion wrong, but if we see a guy in the next draft who's got a higher ceiling than Mills, then we shouldn't hesitate to snap him up.
TKyss, stop me if I'm misrepresenting your point.