They are very realistic by showing what does it mean to be lesbian - loving women, with a side of gender noncomformity (Ruby, post-CYM Pearl). Stevonnie is a gorgeous example of a nonbinary person, as in every appearance they reject gendering and consistently refer to themselves by neutral pronouns. I loved the shaving scene in Jungle Moon, it showcases their biologically nonbinary nature. Most Western series do not dwelve on queerness of the queer characters, saying that they are queer and maybe showing their wedding for a few seconds. In Steven Universe, queerness of the characters is a crucial plot point. And while we don't see Connie celebrating Diwali, her and her parents hit the nail on the "overprotective education focused overeducated Desi parents" trope.