Even if you truly believe that society makes it so that no woman can be said to truly consent to sex (which is a pretty fuckin' dire view, tbh, and not one I espouse at all, but okay sure for the sake of argument we'll allow it as a possibility), you don't increase agency by restricting what people are allowed to do.
You don't improve flawed agency by removing more of it. You don't combat a flawed amount of control over one's own body by removing more of it, or simply by replacing the overlord calling the shots with . . . you, calling the shots.
You increase it by enabling. You increase it by going ok, you're gonna have sex with someone - here are the tools to make sure it's something you enjoy (because you should have enjoyment if you're gonna have sex); and here's the tools to communicate with the other person about you two having fun and enjoying this activity together; and here's the tools to make sure you're both (or hell, even all!) as safe as possible as you do it. And one of those tools is knowing you get to call halt at any time. That it's not actually a huge metaphysical obligation, that there's no actual point of no return (and if someone pushes you beyond your point that's violence), that deciding to have sex doesn't mean you are now for sex, that deciding to have sex today doesn't mean you can't decide not to tomorrow, and that you can decide to nope out today and still totally and without any contradiction decide that tomorrow it sounds like fun.
That being happy with x set of sexual activities has nothing to do with y set and there is no "level" that you cross or increase, there are no "tiers" where if you're fine with this activity that society thinks is outre, you must obviously be up for everything that society considers more "vanilla", and that literally none of this is a package deal.
That you get to say no or yes to each part of it as you like, and so does your partner, and if your expectations don't meet welp that's just a thing that happens sometimes, I guess you're not having sex tonight after all! That your desire to have and openness to having some kind of sex tonight does not mean you're up for this specific sex with this specific or these specific people and that's fine, this is not a switch where you either Must Be Chaste or Must Be Sexual.
You cannot give people the real ability to say no without also giving them the real right to say yes. You cannot restore agency by giving less of it.
You do help restore it by helping to make sure that people know all the options that are available including the ones you'd never take yourself, and by opening the doors to them that way. And then backing them up on their right to make the choice.