I think people are too impressed with total yardage and don't pay attention to what time period it was done in and what was accomplished with it.
If a guy throws for 60,000 yards and 400+ TDs that automatically makes him great? No that just means that he played a long time in a system that allowed/required him to throw the ball a lot.
Staubach played in an era when teams didn't throw a lot and in a system that focused on running first, particularly early in his career. His teams won more than 75% of the time and were consistent contenders. Only a very small handful of QBs can make that claim.
The claim that he had a bunch of great receivers is ridiculous. The years that he led the league in passing he had guys at the end of their careers (1971 = Alworth, Hayes, Ditka) or guys just getting started (1973 = Pearson, DuPree, & Stowe). Only in his last two seasons (78 & 79) did he have a solid receiving corps of Pearson, Hill, & DuPree in their primes. Those were also the only times he threw for more than 3000 yards as the game was changing to more of a passing game.
Roger was head and shoulders above his contemporaries (Bradshaw, Stabler, Anderson, etc.) in almost every category and was easily the winningest QB of his time.