I agree that we should see an end to gendered titles.
I also think it would be odd if I were jane or john Smith, for a caller to just say, oh hello Smith, we're calling about your car service Smith. Or a complete unknown student saying hi Jane, or a cold caller using my first name, which they do as a way of being over familiar/coercive sales tactic.
Sir, and madam, are equally weird.
Also how do you correspond with someone unknown and not be over familiar.... by saying Dear Smith? Or be over familiar and say Dear Jane.
I have written in reply at times using Dear Jane Smith, where a title is not shown, as a best guess at being polite and accurate and not over familiar.
Or maybe we should say Dear J Smith?
Or just dispense wih spoken titles and refer to people by their initial letter and surname, Am I speaking to J Smith
I don't care whether I'm called Ms Miss or Mrs, just say as long as you use a female title, as I'm female, whether I'm married is irrelevant anyway, right?