Or news stations, which hire presenters based on attractiveness.

Or fashion products, which hire models based on attractiveness.

Or the music industry, which puts forward pop stars that are attractive while keeping ones that don't have sex appeal off the air.

Or the film industry. Or the literally any other industry that tries to survive via popularity and getting eye time. Attractiveness sells. What TikTok is doing is no different than any other industry, it's just that the models aren't getting paid.