I think Mahomes is a better QB than Rodgers. He's also better than Brady, despite the # of rings. I think Rodgers is a better QB than what Favre was. I even believe that Favre was a better QB than Aikman. I think Aikman was a better QB than Staubach. I think Staubach was slightly better than Starr. Starr was better than Bobby Layne.
The list goes on, and on. Each generation of QBs is progressively better than the previous generation because of the evolution of the game, and the people who play it.
Even the training regimen has changed over the decades. The old days, of guys driving beer trucks during the off season to stay strong has long gone.
Straight up, as of today, Mahomes may very well be the best QB to ever take the field. I see him doing the things that we can pick out as great from so many different players, and it's all in one body, not spread around with various people. He's just plain a natural at what he does. He makes it look so easy.