Players are different than coaches first off.
Wilt won a championship and was considered the greatest center in the league many years, Jim Kelly was definitely a HOF QB, but was never considered better than Joe Montana, John Elway, or Dan Marino when he played.
Marv Levy could be a similar story to Franklin, but at least Levy would get the Bills to the title game, and regularly beat other great teams.
Franklin pretty much just doesn’t beat other great teams.
1-15 vs top 5… and they regularly have top 10 or even top 5 teams themselves. They just lose the big game that would elevate them to the top tier, like every time lol