Ex collegiate Footballer here. Once you are at the level I was at or higher, steroids are making VERY little difference in whether you can compete, or if there is a diff between two similarly skilled players (b/c all are gifted at this level)
BUT there is absolutely positively NOTHING better than being 'on' during the dog days of camp, AND/OR the late stages of the season when everyone is beat up, tired etc. from such a long grind. My seasons typically lasted about 14 games. The pros are 16 without the playoffs (where you really make your money) you would be crazy not to want to perform your best. And their camp is even longer! I could go on for days.
Prediction1- If they NFL didn't test for steroids, nothing would change.
2- If they increase rules and test for HGH etc. It will be a sad day.