As someone whose directed (nothing anything close to notable but no matter the size the culture remains the same), actors generally don't know what's best for a story or film unless they themselves are directing because its not their vision and its not what they do.
Here's an anecdote from a recent short I did.
Due to time and budget restraints I filmed the basic story out so no matter what I had a complete story I could showcase. Afterwards I filmed a lot of inserts (essentially anything that doesnt include an actor's face such as a close up of a ring or in SW a lightsaber.) that I had in mind of editing in a specific manner. To the actor they seemed nonsensical and unimportant (it was about thirty different shots of fingers rolling, hands adjusting a collar, licking lips, etc...) and at the time they even asked to not do them but when I put together a final cut they immediately understood what I was going for.
The same goes for writing. There were lines actors in my film disagreed with and wanted to change. I stood firm because what they didnt get at the time was how important the way certain things were phrased added to the overall project. In the end the actors got what I was going for and the film was better for it.
One thing you learn in filmmaking, no matter what you do, is that every role involved takes a specific form of thought process. To put it crudely actors, writers, and directors are different animals and that doesn't mean their can't be cross over (take Ron Howard, Leonard Nimoy, etc...) but typically when someone is very talented in one way they are less so in others.
Luke was never Mark Hammil's vision, he was always what George Lucas wanted him to be. Now he's Rian Johnson's vision. So when Mark Hammil says its not his Luke, it never was his Luke. He's had thirty years to aggrandize the character beyond what I think the Last Jedi portrayed as a very realistic evolution a character would have after failing a several millennia old religion he's apart of and more significantly failing his only remaining family.
I suck at audio and producing, those aren't my lane and what you learn in filmmaking more then anything is to work in a team and work with people you trust and respect because you yourself are not good at everything.
Edited by Forresto