Well, if all men wanted to live longer through castration, eventually, there would be no men and no humans.
If men got castrated, would they still have the urges to have sex, and if they do, men and women would have a very poor quality of life, meaning that, life would not be worth it anymore.
If God wanted men to live longer through castration, men would not have been created, and humanity would have beasts with self-procreation properties or abilities. Non-sexual/asexual beasts would equal a totally different species.
That would give new meaning to “go F yourself. “