While he did really proven testosterone's correlation with aggression to be false

I feel like his description of testosterone could still perfectly align with the manosphere advocate "testosterone is the everything good hormone(confidence, muscle gains,etc),if it's an amplifier just use it correctly,must boost testosterone!"

Though i heard testosterone's effect on human body and behaviour is nuances and can be influenced by other factors,I don't really know examples on how testosterone's effect can be affected by other variables.Is there a better study or video(preferred with reliable sources) on testosterone?

Ps. Manosphere influencers would often say that masculinity is dying because the average testosterone level is decreasing, while testosterone level is fluctuated,is this anything to be concerned about