Bart Starr was great, and as Favre a Great Leader, however, he played in an era with little competition and fierce tackling. Starr also benefitted from having - probably - one of the GOAT coaches.
Favre besides being a Great statistical QB also showed true leadership on the field. Favre (seemingly) were able to make his team mates better. Only one losing season in his 20 years playing is a testament to that fact. Favre also played in an era were 3500+ yds were far apart for many QBs in the League - due to defenders being allowed to do more amo (as previously stated by other posters) - and No other player then and now were as tough as Favre, able to take the worst of beatings, but still suit up - also through most of his career Favre wasn't surrounded with the most talented team (1996-97 team excluded) except in 2007 ...
Rodgers is an extremely talented and gifted QB, but he lacks leadership ... and is known to be overly sensitive and arrogant ... Yes Rodgers throws for 4K+ yds almost every season and very few ints, however, in these days QBs throwing for up to 4K and above are not rare, most upper echelon QBs will hit that mark most seasons in todays League. Rodgers has had the benefit of playing on some pretty talented teams, and many consider him among the very Best in the League, if ever ...
Of the 3 - comparatively - I still consider Favre the Greatest QB the Packers had ever had and probably ever will and top 3 GoaT despite only having won 1 SB ...
I know ppl will disagree, but that's my opinion :-P