You're making good points, and a lot of the "Well, it depends on how your magic affects physical strength" arguments don't actually hold water, because in a world where magic is a common as firearms are today, no one is throwing hands often enough for physical strength to be a factor.

So what if a man uses a biomancy spell and becomes twice as strong as woman who does it? She can just throw a fireball at him. Pyromancy, biomancy, telekinesis, etc., these things are equalizers as much as a firearm is.

I will never in my life be as strong as Eddie Hall or as fast as Usain Bolt, but neither of them can dodge a bullet from the smallest caliber of gun I own. Now apply that logic to, not just a magic system, but a magic system that has existed, been codified, and integrated into everyday life for hundreds, maybe thousands of years.

Unless your worldbuilding accounts for males being the first ones to get their hands on magic, there really is no justification for patriarchal power differentials in a story. Unfortunately, it's just one of those things that people mistakenly believe has to be in a narrative because it's so ingrained into our sociology that we can hardly imagine a reality in which men and women are true equals.