Why doesn’t Qui-Gon disappear once he dies? In the clone wars show it’s explained that Qui-Gon discovered eternal life and appears as a ghost to teach Yoda and Obi-Wan this ability. So wouldn’t you have to discover it while still being alive?
Qui gon NOT disappearing is the only thing that gives indication that you don’t need to disappear to become a force ghost and gives reason as to why anakin doesn’t disappear when he dies.