The answer to this is actually pretty simple. A girl's success on selling content isn't conditioned by her attractiveness, but rather the morbid attention she attracts. This morbo can be provoked by being someone who was a part of your past (lets say an actress you watched as a kid for example) or someone who provoked artificial morbid attention (ex. Sophie Rain). Attractiveness is not what matters the most, because you can watch extremely hot women for free on regular porn websites. If you don't provoke morbo, you don't reach success on onlyfans, no matter how hot you are.