Your argument makes no sense. Amateur sex and professional sex are two different things. Just because you can find them crossing sometimes does not make them both just sex. You said this yourself because people can have preferences for either. “Either” meaning x or y, real (majority of videos without acting) vs not real (the majority of videos with acting) sex, two different types, two different types of sex.

While to you it may seem like one type of sex, the mere fact that one is acting and one is real does not make it all just sex.

People prefer not acting, which is the majority of videos in amateur porn. I’m not sure what’s incorrect about that.