I don't think most women truly understand that the concept of a woman being able to take care of herself and her children without resorting to prostitution as a relatively recent societal construct.
I disagree. I think most women do understand it. The fact that it's a new possibility doesn't mean that we should still live like it isn't possible.
It has only been in the past 75 years (generously) that women could arguably do fine without a man.
Just of the top of my head I can think of books like "Little Women" or "Jane Eyre" that happen about 150 years ago, where women are already able to work and support themselves, even if society is still not accepting it as "normal".
130 years ago, women were already accepted as university graduate students in the US.
100 years ago, Marie Curie earned her SECOND Nobel prize (1903 and 1911).
Yes, it's still fairly recent, but it's NOT 75 years. At least for some countries, I'd say women have been able to support themselves for 150 to 200 years. There are of course places where women still do not have this possibility.
It is actually only a fairly recent concept that marriage occurred with common folk
, again. You describe how marriage was handled among nobility in Europe. That DOESN'T mean that marriage was handled the same way everywhere, for the "common folk", as you say. Maybe you are referring only to big weddings, and you are most probably forgetting what is called "Common law Marriage".
Note that sexual monogomy was originally only a constraint imposed on women, and that was to ensure the sire of any offspring the woman produces. Men had no such constraints.
Yet another . "Originally" where? when? under which laws?
Even in many countries today a man caught being unfaithful is punished with a fine while a woman being unfaithful is punished with death. This isn't mysogynistic, this is reality.
As already stated in another comment, reality can be misogynistic, and in many places in the world it is. This doesn't mean that you should accept it as valid, and that you shouldn't take a stand against it.