Anecdotal: I have gone through several moderately long periods of not lifting weights in the last 10 years. The last one was 2021-2022, and the previous one was roughly 2017 (if memory serves) due to some rotator cuff issues (that I was able to rehab after a long period of rest). During those times, I experienced symptoms of BPH or enlargement, although I was never diagnosed. Extended periods where I lift weights have offered a reprieve or reduction.
This is my best theory, because when you get older serum test gives way to more DHT, which occurs in lower levels but has a greater effect on cells. When you lift, and cause muscle repair and hypertrophy, you are effectively using up more of the circulating DHT within the muscles tissues, giving some relief to other tissues like the prostate.
Probably a good reason..................