If there’s one thing I’ve come around to over the years, it’s the non-gender-specific pronoun.
English has always been stuck with gender binary singular pronouns: him-her, he-she, his-hers.
In the past, we were taught to defer to the male when referencing the general human being. We might say “A person might want to get his insurance application in early this year.”
This is obviously sexist, and as a corrective, we came up with the clunky “his or her,” and the even clunkier “his-slash-hers.” These constructions are bad enough in writing, but they’re terrible in speech, and so people naturally deferred to the non-gender-specific plural: “A person might want to get their insurance applications in early this year.”
Technically, that’s wrong: “a person” is singular,” and “their” is plural. The easy fix is to make it all plural—turn “a person” into “people”—but that makes it hard to address the individual case in a non-gender-specific way.
What finally brought me around were the observations of trans, multiple, and non-gender-conforming people, who pointed out that “his or her” doesn’t necessarily describe them, and that some of them actually do use the pronoun “them” for themselves.
So while the stickler in me may still bristle at following a singular subject with a plural pronoun, the human in me is just fine with it.