I think both diet and societal changes are factors and that there is no scientific way to tell which ones cause more testosterone decrease. Whn you watch TV today you see a predominace of "powerful" females that humanity never saw in the history of mankind. Not just as anchors but in sitcoms, movies, comedies, series and of course politics, and those women are not just powerful. They are bitchy, mean, arrogant, condescending, rude. I expect any day now for commercials that show a woman farting and saying, "Smell that one!"
All this is making a fair amount of males afraid of women. I mean, who the hell would want to be married to an AOC, Joy Reid, Jen Psaki or really any liberal anchor or politician? We have a Snow White now who disses on the male heriarchy for Christ's sake. Guys now are thinking, "I need sex but I don't need it quite THAT bad and I certainly don't want to marry that bitch who is gonna tell me she insists on being on top every night." So, they self regulate with their own mind somehow their testosterone levels making it much harder to get a female pregnant.
