If I used all my entitled titles, I (and I suspect many of us) would have more letters before
and after my name than I have in my name (and I have two middle names).
Reminds me of the Monty Python doctor with DLitt (All Other Places in Canada except Medicine Hat) in a nameplate which circled the room.
If people know your background, there's no point telling them your titles. If they don't, and you don't have a big enough reputation to precede you, then there's also no point telling them.
Besides, everyone can have a lot of fun watching pseuds make fools of themselves.
..and only the praise of the praiseworthy is worth having.