Keep in mind that there are a number of things affecting the prostate:
-T and internal T-->DHT
-estradiol and other estrogens
-lack of ejaculation [seminal fluid goes rancid, creating inflammation and free radicals
-smoking and other toxins
Estrogens are thought to be the biggest problem. Note that BPH and cancer are much higher in men with low T and high E, often as part of metabolic disorder that also includes insulin resistance, elevated glucose and increased inflammatory processes, heart disease [endothelial dysfunction] and high BP. Men who are castrated do not seem to have prostate problems. Men with low T do not have a reduced risk as the effect requires castrate levels of T. This does seem to defeat the notion that restoring T to youthful levels will lead to prostate problems. There is good research on this, but I cannot retain the finer details.
Endothelial dysfunction is associated with unopposed estrogens. With men, estrogens are lower [than females] and T competes with E2. With women, progesterone competes with E2. When a woman is in oral birth control [OBC], progestins replace progesterone and the cardio protection of progesterone is lost. Progestins do not oppose E2 in the endothelial cells that line blood vessels. This why OBC can lead to heart attacks, strokes and thrombosis [blood clots].
DHT is mission critical for virilization, development and maintenance of the sex organs and libido. When BPH is treated with a 5-alpha-reductase inhibitor, DHT levels in the prostate are reduced. Without this androgen, the prostate withers. The net effect is that the prostate becomes smaller and urine flow problems can be reduced. However, that really does not address other fundamental disease processes.
Men need orgasms to clear out seminal fluid. When they have low T and or high E2, their libido is gone and they are otherwise likely to have sexual performance problems. These men are trapped in a situation where reduced sexual function contributes to or causes prostate disease functions.