Earlier quoted context omitted.
Of these, the sperm count strikes me as more causal, while the others may be results of some problem. Granted, the decline in sperm count is caused by something, but in relation to impact on behaviors, the decline will cause (as proxy) changes, and of those changes could be the increased medication, for example.
Sperm count dropping is caused by obesity
It may be the obesity decreases sperm count, but sperm count is dropping in people who are not obese. More than a decade ago there were reports on studies where the authors made simple extrapolations that sperm count would be zero by 2050, but these simple extrapolations are holding true in today's trends.