Braindead logic there. Top athletes aren't your average person. If you think Top athletes have lower testosterone than athletes of previous eras just because the general population has lower testosterone on average then I don't think you case can be helped.
Xenoestrogens, fossil fuel pollution and chemical residue in water has have destroyed male fertility and it is 100% true. Truth is most top athletes are on some form of ped’s right now and without them their physiques and performance would suffer. The men from the 30’s and before were a different physical breed. Dempsey from the Willard fight was peak fighting performance due to him being desperate, he was also never the same after that.
It is somewhat more than that. Dempsey was not more than 187 vs. Willlard, he looked at most like a modern MW. Maybe 60-70 lbs. if Fury was not at all overweight.
They have done some harm to male fertility, if it was "destroyed" we could barely reproduce normally. We absolutely do not know if most modern athletes are on PEDs or not. Arguments for & against it are based on broad assumptions on motivations, risk, penalties, ethics-not facts.
Let’s be honest Dempsey looked so vicious in the fight and was able to do so much damage to Jess Willard because Willard was a big stationary target with limited boxing ability. He was slow of hand and slow with his feet. Fury would be way too much for a fighter like Dempsey who would be outweighed by close to 80 pounds and close to 9” in height and 7” in reach.