You managed to cherry pick one amazing player and think it proves a point?
Did you bother to look at the rest of the QB stats from that year? Other than Marino, only 1 QB had more than 28 TD passes. Only 6 had more than 20.
Including Marino, only 3 QBs had more than 4000 passing yards. Only 9 QBs had a completion percentage greater than 60.
And finally, only 4 QBs had a rating more than 90.
Now compare that to QBs from last year and tell me there isn’t a big difference.