... has not been addressed by that example. At all.
There have been loads of famous powerful women in real life, even if we only take European middle ages.
Eleanor of Aquitaine
Adelheid of Burgund
Theophanu
Isabella of Castille and Leon
Hedwig of Poland
Theodora Porphyrogenita
And that is just women instantly coming to mind without looking deeper, so examples exist.
However if asked if i could name powerful
men of the same area and time, i could fill pages upon pages. Powerful women did exist, but were exceptions.
One thing of note however is that unequality based on gender often waas less relevant than unequality based on class. Women taking on the role of men including all privileges and powers, particularly when no men were available in the family, was occuring often enough and in most cases accepted. And no, we don't only have female rulers as the above names might suggest, we have female leads of peasant households, female warriors, female trade guild leaders etc. It is just that rulers are generally more well known.
And yet even with all exceptions, society was very unequal and women in general had way fewer rights in general.
Also it is worth keeping an eye on things like inheritance and whether daughters can inherit. That was never universal but generally in societies where daughters could, women were more powerful.
If we go beyond Europe and middle ages, it was also generally true that matrilocal societies had more powerful women that patrilocal ones. No surprise here as one of the partners keeps their whole support network and the other doesn't.
One actually looks at how human civilisations have more commonly treated women - mothers - and you get the real idea: women as property, expected to be absolutely obedient under threat of physical violence or abandonment, mothers dispossessed of their children whenever it has suited a man to want so. Authority that is utterly conditional on the whim of the father / husband / closest male relative / liege-lord is not a woman's authority, it is just a man's authority on loan.
And while i generally agree with your point that history overall didn't treat women all that well, i disagree a bit on the severity.
The kind of society certain conservative voices want to "return to" is often worse than what existed most of the time. If you go back and look at sources, you often find the conservatives of those times lamenting how the women then and there also are too powerful / intrude into mens places /are not happy with their place as they should.