He reminds me too much of guys like Teddy Bridgewater, Alex Smith, Colt McCoy, etc.
With a good team you can win 10-11 games.
He can throw a pretty moon ball, and make the checkdowns you need, can school a bad defense, and even has solid mobility.
But you doubt their ability to keep up against a good QB in a shootout, or against a good defense that takes the easy stuff away.
Can he threat the needle in the deep middle of the field? Can he throw with enough power passed 20 yards to a so the ball can get there before a safety picks him off? Can he do this consistently? Can he throw a bullet to the character shoulder of the receiver? Can he do this enough that defenses have to change their looks, making it even easier to exploit them? Can you score 30 pts a game with him consistently so that you are winning 13 games can getting first round byes?
I don't think Mac is a bad QB, and he's not being helped this year, but this year is showing genuine flaws he has. Heck, part of why they got Parker and Agholor is to give him jump ball threats to make up for any accuracy or arm strength issues he has.