One possibility with force ghosts is they aren’t the ones projecting themselves… but rather it is the Jedi who are seeing the dead.

I mean, are you seriosuly telling me out of all the Jedi who fought in the Clone Wars only three were deemed worthy enough of force ghost… when one of them slaughtered millions?

Also see how only Luke notices the ghosts on Endor.

My theory is in the SW universe everyone who dies goes to the afterworld. They cannot interact with the real world unless someone they know has mastery over the force.

So if Rey wanted, she could see a force ghost of Han Solo. Because she calls for guidance from the light or whatever. Same for Ben… he could meet both the ghost of Vader and the ghost of Anakin, because he feels the pull of both sides.

I know this has been deemed uncanon by Yoda’s reference at the end of Ep 3 but Star Wars has changed things in lore before.