I think Carr is a good quarterback, I just question his situational awareness. It always feels like he's trying to "win the down" regardless of the situation. Like, if the Raiders are down 7 with 50 seconds left on their own 20 and he drops back to pass--if he doesn't see a deeper pass option he likes, he'll check it down to the running back for a 5-6 yard gain. Which is great most of the game, but a waste in that circumstance. And while he is a good deep ball thrower, I think he's too conservative generally--unless someone is breaking wide open deep right off the bat, he'll pull his eyes down quickly and start looking for his checkdowns or shallower routes.
To me, he's a technically excellent, smart, accurate quarterback who just lacks the juice that top-ten guys have. He's a classic "Gruden Grinder." But it'll be hard to upgrade on him, because to do so, you need someone in the top tier.