Win/loss is a team stat.
Drew Brees led the NFL in passing three years in a row, his Saints offense was top five, his defense was ranked dead last.
Brees went 7-9 three years in a row. It's a team game.
Brissett's stats as a starter aren't eye popping, but he's efficient... he doesn't turn the ball over.
After points, turnovers are the most important stat in football, because they most correlate to points.
If Jameis Winston could stop turning the ball over he'd be Warren Moon, if Mac could stop turning the ball over he'd be Kirk Cousins... neither can stop turning the ball over, so now they're pinned to the bench.