Do you have any examples for me where a director became an actor or actress? I've heard of it going the other way around, like with Tom Cruise, Ron Howard, and Ben Affleck. I think it's interesting and I can see why they'd be able to make the switch since both require a creative mindset.
Mel Gibson comes to mind. People like that, I believe, really love the trade itself more than just acting. The side benefit is that they're not in the limelight when they direct, and that has to "play a part" as well I would imagine.
Is it easier to produce or direct a film rather than act in it? Well, I think this varies from one person to the next. It could be that those that make the switch feel that they are more talented in working behind the scenes in comparison to acting, and vice versa.
There seems to be a higher tendency of actors or actresses switching to a directing career instead of the other way round. I’m thinking if they can no longer find satisfaction in acting any more. Directing a film allows them to express their thoughts and ideas in better ways I guess? Can it be a reason?