Yeah, cisness or transness isn’t an essential attribute of the body/mind/etc., IMO. But insofar as there’s still some use (pragmatically, in our world as it is today) in pointing out who’s done some kind of gender/sex transition and who hasn’t, we can at least use a word pair that doesn’t privilege one type of human over another. My position is: If someone points and says “Those people are trans,” one might respond: “And the person who’s noticing? What are you?” (Cis. Just because it’s the opposite of trans.) It helps people to see that they are a person-who-marks-trans-as-different-from-themselves. Helps them to notice what their mind is doing when they make this particular distinction. If people don’t like or find use for the word “cis,” they should question why they like or find use for the word “trans.” Thus, the itchiness that many people feel at the word “cis” is part of the point of using the word. It’s not to be rude or cruel, but to reveal uncomfortable truths that only come from disturbing the water. It shows them that they too have a standpoint and they speak from it, and they are not the neutral arbiters of gender/sex for everyone else. If they never ever ever want to be called “cis” on the grounds that it makes them feel itchy and/or doesn’t describe anything meaningful, they must straightaway cease calling anyone “trans” for the same reasons. Once people are no longer singled out as “trans,” then “cis” won’t be important either.