Models are paid to be very, very good-looking. "What you produce" is a value decision in the first place, one that society makes together by how we allocate resources.
Not what they produce, but how good they are at convincing other people to give them money. Whether it's by building a product, being very good-looking, or asking for a handout. (Sure you can say that we pay people based on what they produce if you argue that a homeless man is producing good feelings when you donate to him, but I think that's a bit silly).
Obviously this is always going to be the case to some extent in a free society, but we should definitely do more to help those who don't happen to be good at convincing other people to part with their cash.
Models are paid to be very, very good-looking. "What you produce" is a value decision in the first place, one that society makes together by how we allocate resources.