Are there any English words that combine the meanings of "he," "she," and "it"?

Singular they , appearing of course just as "they", can be used only to refer to “she” or “he” as a gender-neutral third-person pronoun, for instance The murderer was wily; they never once exposed themself to a CCTV camera. [gender unknown or kept under wraps] Why is “they” only used with plural agreement when referring to an it , that is an inanimate object / thing or gender-unspecified non human…