Most people don't have actual submissive sex on purpose. D/s relationships with full awareness of the nature of the relationship are not very common.
Yet we can say that most women play a submissive role in relationships and are constantly coerced to sex. (I'll feel bad if I say no to my bf, I'm afraid to correct him so he makes me cum, etc) Most of the time not even men are fully aware they are coercing their partner, they are just spoiled, poorly raised, and expect everyone to cater to them.
In this case, it is not submissive sex that results in oppression, but rather gaslighting, negging, and oppression which primes women for "natural" submissiveness.
People who partake in Dom/sub relationships, and women who have submissive sex willingly, are fully aware of what they are doing, or I at least hope they do. Being submissive with an actual partner as a woman doesn't "contribute" to society or harm other women, because unlike women who are unaware of their submission, submissive women know about relationship dynamics. There is a certain kind of dominance they expect from their partner. They have boundaries. They can tell the difference between a dominant man and a pampered one, so when the relationship doesn't serve them, they just dump the guy. They know that being submissive doesn't necessarily mean servitude.
Women who are primed into submissiveness by society have no boundaries. They think that they have to be the perfect, hairless, anorexic doll to please a man, any man. They have no confidence and they are afraid of disappointing their partner, so they will let the man do anything regardless of how uncomfortable they are, because "If I say no, I'm not the perfect doll, he'll hate me," etc. Moreover women who are primed by society think that they need to "put out" and have sex with a man they don't fully trust or like, because otherwise they'll be called a prude, and that's bad.
If you call yourself a submissive but feel like what I said describes you, you're not submissive. You are not ready for this fetish, and it may not even be for you at all. Submissive sex is consent based while oppressive sex is not. >>135083
I don't think sex acts are inherently submissive or dominant. It's really hard to imagine a world where being "penetrated" doesn't exclusively make you submissive, but with experience I've learned that dominance/submission is not about the act but rather the attitude. A man can perform oral submissively if he acts meek, looks up at you like a little puppy, whimpers throughout, and generally acts as if he lives to serve you. A man can perform oral dominantly if he makes you flustered first, acts confident, pins you down, gets up and praises you for coming for him after. Dominance and submission is greatly psychological (as is most of sex) and setting the mood with the right attitudes is much more important.
Being the "penetrator" isn't what makes you think that you're dominant. It's oppressive society which primes us for the idea, because men rule the world, men are the ones who penetrate. For misogynists it's convenient that most women are primed into thinking sex naturally involves them being submissive, because most sex involves PIV. If genitals were swapped but women were still smaller and weaker than men, I'm sure being penetrated wouldn't be considered "submissive" by men's society.