That does not mean they are necessary. That means there's many of them. Women's role in healthcare is not that important. Doctors and surgeons are overwhelmingly men. Women are mainly nurses and caretakers, which are frankly disposable when it comes to the functioning of society. As for teachers, that is the most overrated and unnecessary profession in existence. Every school could be burned down to the ground and society would work equally as well. But even if we wanted to keep schools, the fact that there are more women teaching children (as opposed to college professors, which are mostly male because their discipline is actually relevant) just proves that women like children more, not that they are better at teaching. Not that anything children learn in primary school is useful in the first place. Women do not play any vital role by being primary school teachers. On account that this wasn't the rule until the 20th century and somehow society worked just fine for all of history until then.
There's not one thing women have ever done better than men as far as contributing to the social structure. You're absurdly delusional if you think a CEO goes, "Women are better than men at doing this job, so I should hire them if I want to increase my profits. However, I won't hire women because that would be giving them power and I am so misogynistic I'd rather lose money than hire women to increase my company's profit." Is that how it works? Could it be perhaps that women aren't hired for important positions because they're not as good at them? And you don't get the excuse of "we're so good but they won't let us try", because in the first world, women can do whatever they want and they still don't excel at the level men do. So it ain't because they don't have the opportunity to succeed.