It is not close. Not even remotely close.
Allen is the most productive player in the history of the NFL on a per game basis in both the regular and post season.
Allen is literally doing something nobody has ever done before 5-6x a season or more.
Kelly threw more than 30 TD passes one time. One!
Allen is so much better than Kelly it's a joke anyone would even compare them, let alone put Kelly higher because they have some nostalgic bias of misremembering Kelly's play here and thinking it was far better than it actually was.
Kelly was very good, but he was never even close to Allen's level either in play or talent.
And that's simply the inconvenient truth many don't want to admit. But I watched every game Kelly played in as a Bill and never saw Kelly do anything close to what Allen has.
Not even Jim Kelly himself would say he was better than Allen. No need for anyone else to.