Alright, I've seen a lot of confused posts (especially on my bsky excursion) so let's talk about top and bottom.
So, the definition I see most commonly outside of bdsm spaces is "the top is the penetrative role and the bottom is the penetrated role".
This is a useful definition for assigning one character "basically male" and another character "basically female", as penetration is understood as a defining element of masculinity (with the ability to be penetrated a defining element of femininity).
However, in bdsm spaces, we commonly deal with activities that don't involve any penetration, so instead we define it as: "the top is the leading or active role and the bottom is the following or receiving role".
Thus: In bondage the rigger is the top and the rope bunny is the bottom (but bondage is complicated and not even necessarily a two party activity so these definitions get weird a lot). In discipline the one doing is the top and the one being disciplined or having rules prescribed to them is the bottom. In D/S the roles can vary and be multidimensional, but as a rule the dom is expected to be the leading role and is thus the top while the sub is following and is thus the bottom. In S/M, the sadist is the top and the masochist is the bottom.
We can see here the utility of top/bottom language to bdsm. Providing a way to generalize roles across the various parts of bdsm in ways that generally make sense.
At the same time, mmm. We're still kinda just ascribing binary gender roles to kink, right? This language seems to imply that there's always a doer and a receiver, and that these things follow along lines that line up pretty closely with gendered expectations. Shouldn't we try to be less binary?
It's complicated. Two is actually a really useful and important number, and all relationships between two parties can be expressed in 'binary' roles. Your critiques of binary labels must be more complicated than "looks like gender and is therefore bad", because, uh, at some point that just becomes anti-language and increasingly anti-intellectual.
This language certainly does tend to recreate gendered concepts. I'm not sure if there exists language that is both useful and doesn't do that, though?
But, hm, I think one way to make the language less 'gendered' is to point out the ways in which the bdsm definition of top/bottom actually differs from the non-bdsm definition. Because it's extremely easy to be both the penetrative role and not the leading party.
To give my favorite example, oral! Under any coherent understanding of the bdsm construction of top/bottom, the one receiving oral is the bottom (as, uh, they generally don't do that much, except talk and make noises, but their body does most of the talking. in my experience, oral has a lot in common with s/m.), and the one giving is the top. We even see this dynamic emerge in the language of giving/receiving.
Of course, there's the illusive 'facefucking' where the one with the genitalia does all the work and is thus the top, but in my experience this is relatively rare and significantly less enjoyable to the one riding the other. It mostly seems to emerge from those inexperienced in giving head but uninterested in learning, or rape kink havers.
I think in 'penis in vagina' activities, the spectrum of bdsm-type top/bottom becomes more complicated. Someone who is familiar with different positions might be able to list off who is the top in each position.
But, in any case, my point here is. The way you make top/bottom less 'recreating the gender roles' is you apply it critically to gendered dynamics.
At the same time, I don't think you can ever fully get rid of the implication of a more masculine and more feminine role. But, I think this is a fundamental flaw of language. Language will never be perfect, it will just be more or less situationally useful. And, from the set of situations we observe, we may foolishly attempt to argue for more broad utility to it.
