comeliness vs. charisma
Comeliness is already under the umbrella of charisma (PHB p 9):
Charisma measures a character's force of personality, persuasiveness, personal magnetism, ability to lead, and physical attractiveness.
perhaps more important is the second sentence:
This ability represents actual strength of personality, not merely how one is perceived by others in a social setting.
So, the following statement doesn't accurately represent Charisma:
Well, this is true, but people do not seem to have much problem with charisma and I can assure you that 'personal magnetism' and what type of personality is liked also vary accross cultures and would vary enormously accross species. Neither is universal, so why is the idea of comeliness so much less popular than that of charisma?
Charisma has nothing to do with the perception of others in social setting. It is universal and already covers personal beauty.
As a side note, to add another stat that would be marginally useful (I can see a "seduction check," perhaps) seems a waste of time... unless you're running some sort of kinky game, in which case I recommend real life people.
Just my 2 cents.
Comeliness is already under the umbrella of charisma (PHB p 9):
Charisma measures a character's force of personality, persuasiveness, personal magnetism, ability to lead, and physical attractiveness.
perhaps more important is the second sentence:
This ability represents actual strength of personality, not merely how one is perceived by others in a social setting.
So, the following statement doesn't accurately represent Charisma:
Well, this is true, but people do not seem to have much problem with charisma and I can assure you that 'personal magnetism' and what type of personality is liked also vary accross cultures and would vary enormously accross species. Neither is universal, so why is the idea of comeliness so much less popular than that of charisma?
Charisma has nothing to do with the perception of others in social setting. It is universal and already covers personal beauty.
As a side note, to add another stat that would be marginally useful (I can see a "seduction check," perhaps) seems a waste of time... unless you're running some sort of kinky game, in which case I recommend real life people.

Just my 2 cents.