Johnny Cash recorded a song that's relevant. Wikipedia has a lengthy entry full of unisex names from around the world. Surely, someone, somewhere in the world makes up a new name every day. Based on a person's name alone, there's no way to assign a salutation with unattended automation without substantial and sustained effort and still not eventually fail in a potentially easily embarassing way. Much easier and safer to provide a field for users to fill in their own desired salutation. Bonus points if it's a text entry field instead of a dropdown list, for the same reasons that #24 through #29 are listed in the parent article.

It is even better when the assumed sex changes depending on what country you are in

...and what decade.

https://www.scarymommy.com/girl-names-formerly-boy-names/

I think GP was rather referring to names such as Andrea (which is a traditionally female name in Spain, but traditionally male in Italy).

I'm aware of this, having such name myself. Border control agencies eye me with various degrees of suspicion for this, depending on what gender my name is supposed to signify to them. (Yes, that's in the passport as well, but...well, bureaucracy)