That word castration is a bit harsh. It isn't permanent castration. You take a hormone blocker during your therapy. But when you're done and you stop taking the blocker, testosterone production resumes.
It will accomplish the dr's desired results during the time it is administered. The guy will have no sex drive. No sex drive is actually not unpleasant. Since you have no desire for sex, it's not like you miss it. You don't go thru the day having periodic bouts of being horny. You aren't controlled by your dick needing attention. Also, you don't feel the aggression that comes with testosterone. No road rage. Haha
Life is much calmer without testosterone.
Been there. Done that. Even got a certificate afterwards!