I dunno, Darth Vader is pretty evil-sounding. It makes more sense that Anakin changed his name at some point to something more sinister. The issue is that Darth became a title given to any goofball with a red lightsaber instead of a unique first name.
I always thought it would have made sense that Jedi adopt a new ‘Jedi Knight’ name after being knighted - kind of how Pope’s take a new name. That way “Ben” Kenobi would have been his rightful name, and “Obi-Wan” was his Jedi name.
Which would explain why Anakin Skywalker took “Darth Vader” as his name - once he was ‘no longer the learner’ - it was his new name to indicate he had completed his training.