Redo of Healer is titled that because he is the "healer hero" of the party and is literally given a redo of his life after they kill the demon lord in the first chapter.

Also, most of the time the titles are either puns or kanji (aka a single character that takes like 3-7 words to spell out) in their original form. So once its translated to any other language it loses all the reasons it was originally made that way.