With any actor, the first question you should ask yourself is “Whose kid are they?” If they are the child of a normal, non-Hollywood American, they may have gotten to where they are by grit, hard work talent and a fair bit of luck. If they are the child of Hollywood Royalty, they got to where they are by having Mommy or Daddy make a few phone calls. The latter type are probably no more talented or attractive than the clerk down at the corner store, and almost always have an obnoxious sense of entitlement.
Gwenneth Paltrow, for instance, is the daugther of Big-Time Hollywood Producer Bruce Paltrow and actress Blythe Danner. Surely she started life on Third Base and thinks she hit a home run when she gets to walk home. She’s a reasonably pretty girl, but what’s the fuss?!?
The rest of your post explains the fuss.
Hollywood is an inbred, elitist aristoracy of fame. Inherent in such a system is that your position is based heavily on who you are, somewhat on who you know, but very little on what you do.
Hence, the daughter of Hollywood royalty is herself royalty by birth.
The priority list continues with political correctness, physical appearance and accumulated body of work. At the bottom of the list is talent and acting ability.