This happened to me in the USA. I told the doctor I want to be sterilized and neither my husband nor I wanted kids.
He told me it would be unethical. My husband might die and then my new husband would want children. I told him I would not change my mind, and such a man would be incompatible for marriage with me. He told me I’d change my mind. So basically, yes some hypothetical future man would want to use me for a baby factory, that’s why I can’t be sterilized.
I was 30. I’m older now, still don’t want them. I’m too ashamed to ask again for sterilization. My husband has a vasectomy scheduled soon (weird how a doctor had no problem doing that for him. Wonder what the difference is???)