Because it’s harmful chemicals. Your brain and mind become dependent. It can cause your behavior to change in ways that are risky and deadly, or make you a zombie.
That being said I still take meds, and doubt I will ever be able to quit. Perhaps I need them however I can’t say they have made my life better for sure. Tread carefully and make a journal of how you feel every day and look to lifestyle and diet changes, therapy, meditation, etc before going on meds.