I’m not suggesting avoiding soy altogether, just cautioning against excessive consumption of it. Studies are showing mixed conclusions, but it’s not all fear mongering:

Study showing some effect: https://pubmed.ncbi.nlm.nih.gov/15735098/

Study showing little effect: https://pubmed.ncbi.nlm.nih.gov/11880595/

While the evidence is inconclusive, I wouldn’t take chances if I were trying to have kids. I would imagine getting __all__ of your protein from soy could potentially be harmful, perhaps even in ways other than decreasing testosterone and sperm count.

In general, everything in moderation is best.