Look, you are just flat out wrong about singular they. Singular they is used all the time in conversations. Even Shakespeare used singular they to refer to a person. Hamlet act 3 scene 3 line 34.

Personal pronouns aren’t new either. The bible gives God personal pronouns, He/Him, since His pronouns are always capitalized when He is referred to.

Grammar isn’t being made up, the tools that already exist are being used in ways that make you uncomfortable for some weird reason.