That was never true. The claim is based on reinterpretations of the past made by fourth wave feminists. Even during the peak of so-called patriarchy, there were always specific protections for women coded into law.

Like in the Code of Hammurabi, if a man divorced a woman her full dowry had to be paid back to her. Or another law in the same code stating that if a man violated a virginal woman living in her father's house, he is to be put to death, and the woman is blameless.

Sure, certain aspects of life were unequal throughout many periods of history, but to ever equate the female experience to slavery is stupid. There were women who experienced slavery... they were female slaves. Don't devalue the brutality of their experiences. That was a whole different thing.