If a girl is young and attractive, she can get away with anything, even if she doesn't have an amazing personality and she's kinda boring or superficial and/or vapid, other people will not notice these traits and put her in a pedestal (or if they do, they'll cut her slack and try to find excuses for her behavior "she's young and inexperienced, so it's ok"). She can even get away with being slightly rude to others or arrogant (in this case rudeness is perceived by other people as honesty and arrogance=confidence), as long as she doesn't commit any major transgressions.
If you ever dare to argue with them or point out something negative they said, other people will tear you apart and call you "an incel" or a "jealous hater". Most people tend to rather pretty oblivious to the effects of the "halo effect", so they won't easily admit this.
Disclaimer: I'm not insinuating that all pretty girls possess these qualities, or that they have a bad personality, (I've actually met some pretty people, who were also kind, funny and had a great personality) or hating on them but from what I've noticed both online and in real life, overall they tend to be treated much better than other people.
