Testosterone isn't 'king', in fact it's a hormone which will drive you to death. It's surrounded by health implications such as prostate cancer (balding or bald men theoretically have a greater chance of developing this, due to a sensitivity of androgenic activity within the body), and cardiovascular issues. It might be somewhat important in maintaining masculine traits such as aggressiveness, but that does not mean it's a leader.
I started balding at fourteen years old, in which it became noticeable to myself at eighteen, which is the age I decided to start treatments. It's not about what people perceive of myself, but my own particular perception. Hair is great, it's comforting to be able to sport particular hair styles and feel confident about it; that's due to my own personal valuation of hair. Of course, it will lead to further success within life since hair is seen as a trait within the umbrella of beauty, but that's one aspect.
A man who lives life without testosterone is still a male, but they just lack a hormone. It's similar to how women have a significant reduction in estrogen once they hit the menopause; they're still women, they didn't somehow become a male due to it. I feel more motivated to get out of bed without testosterone, especially due to the benefits of ADT such as clear skin. It's a confidence booster. Nonetheless, it's not recommendable to live life without sex hormones which is why estrogen therapy is important.
I'm not sure why you are commenting about his self-castration, and mentioning about hair loss and self-esteem, when he has already done the deed and nothing can be done about it. It just seems as if you are commenting just to criticise, which is a common theme within this thread.