Repeating the mantra that transwomen are women does not make it true. You have every right to live your life however you want, including taking drugs that change your natural hormonal levels. But male DNA is not changeable. The size and shape of pelvic bone is not changeable.
So in taking HRT I've changed the DNA in my cells from male to female. It has to do with transcription factors and the hypothalamus. As a felon I had to give a new DNA specimen for NCIC when they found out I was on hormones. Yes it changes, even orgasms change! I can have multiple ones too.
Actually the genetics of every cell changes. You produce the same estradiol in your ovaries that I take. But the cells all are half male, Dad/female, Mom. T reads the male links in the cells. Taking E shuts down the male part and activated the female links. My cells know how to make boobs.
Boobs are secondary sex characteristics and growing them is not what makes someone female.
Now you and I both know a woman who has a double mastectomy feels less of a woman. It takes courage to face the world after that. Breasts are a major sexual characteristic. What's the first thing a guy notices about any woman? Living as a woman makes me a woman BTW.