Your sister very sadly died because she had cancer, NOT because of taking or not taking a drug. Secondary breast cancer is the threat we all live with and it strikes those who take hormone therapy drugs and those who don’t.
Although I have chosen to discontinue my drugs, I have NEVER advocated that anybody else should do so. Each of us chooses our path by weighing up what we want out of life. For my part I choose quality rather than longevity but the majority of people will choose a different way.
This is obviously a subject you feel strongly about and you are one of the fortunate in that you do not suffer side effects. You might find it more helpful to develop your understanding of why people discontinue this line of treatment by perhaps finding out just how intolerable life can be when the side effects are devastating. My life is important to me and I have no wish to die BUT I would rather live freely in the years I have left than simply exist as an old woman crippled by pain.