Okay...so what is their charisma against a blind person? Or a person from another species? Or who just has a different definition of "smoking hot"? Maybe someone of a different orientation, or who is asexual? I would suggest to this player that their definition of charisma is incoherent."I have a high Cha."
"Oh, is it your magnetic personality?"
"No, as it notes in the rule book, it could be based on attractiveness, I'm just smoking hot."
"Oh, ok cool."
Or, if that really is their sole reason, then their charisma only counts as high when they are trying to make, say, a persuasion check against someone who holds similar standards of beauty and might find them attractive. But against most others it will be a 3 because, sorry, but by their own standards charisma depends entirely on how attractive you are to the other person/creature/cosmic entity.
Also, they are good at sorcery because they are "smoking hot"?
Edit: this is another problem with tying charisma to attractiveness. Beauty is not objective. It is absurd to suggest that someone who is attractive to some humans is therefore also appealing to an ogre, a dwarf, a black pudding...
But my bottom line is that this BS message, that how you look is the most important thing about you, gets repeated enough in the real world without it needing to be in the game. It does actual harm on a vast scale.