Jerry Rice did the most with the least amount of talent than the mega wide receivers. He did so with outstanding work ethic and he kept his body in tip top shape. If Randy Moss had Jerry Rice's work ethic he would have been the greatest of all time
Also, Jerry Rice got as lucky with his quarterbacks as Emmitt Smith did with his offensive line. You can't fault him for it, but it's just the luck of the draw. To go from Joe Montana to Steve Young to Garcia to Rich Gannon, it's not like he had Kerry Collins as his quarterback
Sometimes it's better to be lucky and good. I don't think we'll ever see a receiver play into his 40s ever again and Jerry Rice played until age 42