A very modern convention is now using “they/their” when a person may not be aware of someone’s preferred pronoun. And even still, I have also seen people abandon gendered pronouns entirely.
It's also a very old method. In fact, he/she is a later evolution of the English language. "He/his" used to be more equivalent to "it/its". It wasn't until ~15th century that the modern "he/him" and "she/her" fully evolved. "They/them" meanwhile was in full use by the 14th century
It’s also just far easier to use a plural pronoun to refer to a singular person to reflect the idea that you’re talking about their whole persona, brand, work, etc… and not just specifically the human being, IMO.
