What’s in a title? In my opinion the only answer is a minefield. If we just stick to the English language we have (in no particular order whatsoever): Mr.; Miss; Mrs; Ms; Fr; Sr; Dr; Prof; Sir; Lord; etc.
Long before pronouns became an issue, one half of adults had the minefield exposed on every formal communication they received.
I know that within religious congregations the habit of addressing fellow members with a title is partly a recognition of the shared community, hence “Sister Alice” or “Brother Bob”. It is a way of showing the shared community in their religion. But outside of that context does Bob or Alice get upset if we call then without their title? How would they feel if an atheist or someone from another religion used the “Sister Alice” title, which is really meaning “fellow believer”, especially if the person using the title is not a fellow believer!
Then there’s academic and medical titles. Here things can get really complicated. Take Ireland’s hospitals for example. Suppose you need to see someone for your heart condition and your GP says he can make a referral to either Ms Brown or Dr Smith. Who is the more qualified? That would be the consultant doctor Ms Brown. Everyone amongst the doctors in a hospital are doctors, so in Ireland (at least) the senior consultant doctors distinguish themselves by being called “Mr” or “Ms”… reportedly they can get quite upset if junior doctors call them “Dr”.
In academic institutions, not everyone in a Professor. For example in Irish universities there are multiple grades of lecturers, only the top two, Associate Professor and Professor, have the entitlement to use “Prof” as their title…
There are also a lot of very qualified women who put a lot of work into getting their PhDs. I think it is entirely legitimate to complain if you have a PhD and someone calls you “Mr” or “Ms”.
Don’t even try and get an Irish person started on discussion of hereditary titles or other titles assigned by royalty.
So what to do in this crazy world?
Here’s my answer, use whatever title someone asks you to use. If you don’t know their preference then just don’t use a title.
It’s kind of like pronouns really, if you don’t know what Fran’s pronouns are then just keep using Fran rather than substitute a potentially incorrect pronoun! If Fran gets upset at the repeated use of Fran’s name in place of Fran’s preferred shorter pronoun then Fran can tell you Fran’s preferred pronouns and make speech directed at Fran less cumbersome!
My preference is for people not to use a title.
Just call me Stephen. (Hint: the “ph” is pronounced like a “v”, so please respect my mother’s spelling choices, say “Steven”, write “Stephen”)
If, as is increasingly an issue with the people I know’s choice of life partners, you are in a situation where there are multiple Stephen’s present, Stephen C works quite well! (Apologies to Stephen D and Stephen G)
And everyone I went to school with will just keep calling me Stephen A to distinguish me from Stephen S Connolly with whom I shared quite a few classes!