They're trying to say that if you're born to (successful/married/privileged/whatever you want) parents, that will have more of an effect on your outcomes than your attractiveness.

But that's orthogonal to the question. It's probably true that Zuck's kids will do better than mine (though that also depends on how you measure things) but that doesn't change whether they'd do better if they looked better.

School doesn't start at university, and social reproduction is not a myth. Look at the cohorts of top universities/programs.