Capacity in WHAT?

And you do know that things like body strength, and even blood cell count are not inviolably separated between men and women, right? A female cyclist will make far more blood cells than a man who sits in an office chair all day. Same goes for strength. The theoretical maximum for males may be more than it is for females, but that is entirely meaningless in discussing men and women in daily life. Unless you think they're depicting the strongest man vs. the strongest woman in Force Awakens using slim and entirely physically unimposing Adam Driver and Daisy Ridley...

I don't know where to even begin here, but lets start with this: what makes you think that such dimorphism is static? Further, that such dimorphism is purely genetic, and has nothing to do with social and behavioral pressures?

Designed by whom? God? Because evolution doesn't work by rules of "design".

And this is not at all genetic (even if we take the numbers for true)! Just because it is so doesn't mean it has to remain so. The problem is you're assuming physical weakness is a part of being feminine, as if that is some genetic truth that can never change. Even genes can change, given the right pressures, but there is no evidence that we need to do that. A lot of women have the potential to be a lot stronger than they are. But from a very young age they are told training their bodies and indulging in physically strenuous tasks is "for boys". So of course you see a lot of women weaker than men. Its a self-fulfilling prophesy.

And since Rey and Kylo Ren were using weapons, and non in a wrestling melee, what is the problem?

Look, resorting to (questionable) biology isn't an answer anyway. You can, and do, see justifications for things like rape, sexual harassment, and beliefs on female intelligence based on "biology". But as a society we firstly do not let the "laws of the jungle" rule us, and secondly, aren't much beholden to them anyway.

By the very same ideas of biology you were spouting above, democracy isn't very sensible either. The same sexually dimorphic animal societies use brute strength to enforce the superiority of more physically powerful males. Where was your outrage when the more slight Luke was able to battle the much more physically imposing Vader, then? Or, indeed, Yoda matching Palpatine strength for strength?

Why don't you insist that only the biggest, strongest men be shown as winning physical fights, since "using a weapon" is somehow reason to say that those instances of women abusing men should count for less? And why not use the same standard for naming our leaders? The man who can swat away physical challenges gets to lead, right? After all, some animals do it, so we should too...