So, you may or may not know this, but an early Kaine design involved her being almost 100% clothed.
You can see in the illustration labelled [45] that Tyrann wasn't designed as a part of her physical form yet (or perhaps it was just her lower body? This is pure speculation).
Anyhow, I think Kaine's final design is a powerful one. She's possessed by a shade who has turned her from female to intersex (excuse me if that comes off as offensive in some way, I don't often speak of genders/sexes and no offence is meant) and who also is physically visible in the form of the black scrawl on her left arm and leg. Kaine's clothing of choice is one that aggressively expresses her femininity and human form (note the coverings on her left arm and leg) as much as possible while still being clothing.
I personally don't really have any issues with her costume because the game doesn't really objectify her. She has tons of agency as a character, as well. 2B is also handled super well in these regards. Her outfit is an expression of what the Androids feel a female human would wear as they chase their image of ideal humanity, and frankly I don't think it's out of touch with reality in that regard.