Allow me to make an argument, then.
Maye has elite size and arm talent. McCarthy has very good size and arm talent.
McCarthy makes faster, better decisions. He makes far fewer mistakes and isn't as reckless with the ball.
I'd say McCarthy gets a very slight edge in mobility. I think he's better throwing on the run than Maye is.
McCarthy is more consistently accurate. He's got better footwork. Maye has better touch.
McCarthy is more NFL-ready, coming from an offensive system that required him to take more snaps under center and relied heavily on play-action.
By all accounts, McCarthy has A+ toughness and leadership.
In short... McCarthy is less of a risk. He's more likely to be a good NFL quarterback, and while I concede that Maye has a bigger upside, I'm not convinced there's a huge difference.