To me, a generational QB would have to consistently elevated his team well above their grade throughout their career. Especially when the pressure is on, under the bright lights.
John Elway was generational, no question. Elite talent that took 3 rather average teams to the Super Bowl. Yes, they lost all three by wide margins but Washington, NYG, and the 49ers were far better teams. Later, adding more talent, namely Terrell Davis, put the Broncos over the top. Still, no Super Bowl without Elway.
Dan Marino didn’t get a ring but had rare skill as a passer. Broke records that had stood for nearly two decades, only to have them broken nearly two decades later. Don Shula has two legacies. His first was the 1970s three year run of SBs (2-1) and the undefeated season, and his second in the 1980s, failing to build a team around the best pure passer in NFL history.
Aaron Rogers? 4X MVP, he rules the regular season but his playoff record? Meh. You could say he is his generation’s Marino, and I wouldn’t argue, but still…. multiple playoff chokes….and the game is far more passing friendly than in Marino’s era. Almost a different game.
And yes, a player can be a HOF without being generational.
We probably need a different adjective.