Why are they busy? Because those people (actors) are close to the business, they know where what will be filmed, they know where who is looking for a role, so they shove their branches there. But it's not just in acting, it's in every craft or job. . There are families of doctors, car mechanics, bankers. Talent probably doesn't work very well here, but since the new adept is closer than another person, he knows better than the other how to do it. I think there are a lot of inferior actors who, of course, had brilliant acting ancestors, but they themselves will never achieve the fame of their father, mother or grandfather. Maybe it's about the luck of the roles.