I know a lot of teams would be a lot better. But would this team be a Super Bowl contender with Mahomes as the QB?
NOPE its play calling and the offense hes allowed to be successful in..sorry its not the QB, you are looking at great Offense with pay caller who tailors the game for Mahomes that makes that offense so successful with Mahomes talent.,
but sorry he doesn't instantly make any team a SB team but for sure increases the odds.
we are talking about maybe 3 qbs a decade or less than 3 called Elite that can carry a team. there are 32 teams look around at qb play this year , Not many capable of being great on their own... teams still win and without play caller in an offense like that that design guys open and know how to attack weakness of the other team and solid d, good TS etc etc you won't win with just a great qb.. Andrew luck , dan Marino are few come up right away. Many great qbs have not succeeded to their actual talent level suggested they should as they ended up on the wrong team.
Better to have great team play then a great qb as those dont grow on trees.
many less then steller qbs on great teams lie Eli, Dilfer, Flacco, Foles, and others have won SBs because of team play was elite vs one player.