Even looking at Cam's MVP season, it wasn't a great year from a statistical perspective. He only threw for 3800 yards, with just under a 60% completion percent. That is an absolute shit completion percent. He did throw for 35 TD's versus 10 interceptions, which is not a bad figure. He also added in an additional 600ish rushing yards.
But his team went 15-1, and he had decent numbers for a QB, so he kinda won by default. His best statistical season as a QB is probably still not even top 20 all time.