I'd like to think a company run by a woman wouldn't be really sexist, but I learned at one of my very first jobs (17 years old) that this is not always the case.
Sometimes, you work with other women who are really freaking awesome (I have a few at work). Other times, you get women who are very very paranoid that other women are competition so they surround themselves with men and wall out any/all other women (who aren't their own bffs) and lean hard into the sexism as a means to protect their own position in the framework of the company. Unfortunately, I think the upper echelons of my company are just that.
It's why the report I made was so fucking disheartening because when I sat down with HR and a manager, the manager was a woman and she just sat there looking at unrelated paperwork like the whole thing was nbd and a waste of her time.
I've treated her politely and openly with respect since, but privately I have absolutely none for her.