We all know about that concept. But when I read stuff here I'm not sure if the problem is the concept itself, or the impacts/importance it is given by TRP.

In my country, women themselves tell me how much shallower young women are and how much their tastes are going to change later. But this is presented as a good thing, beneficial, especially they tell it to me because I'm typically not the alpha young women want to fuck but more the beta women want to marry.

This is a common belief and people tend to think that AWALT and it is understood as an unconscious behaviour. Even though, hookup culture doesn't feel very strong, serial monogamy is the standard model for all ages.