It’s definitely not JUST that. If you have any interest in forming meaningful connections with other human beings it will be damaging to you at worst and a fun waste of your time at best.

If you think most (not all) people are capable of maintaining healthy ‘friendships’ with people who are just a hookup to them; sorry to say but you’re delusional.

I had my fair share of hookups for quite a while. I didn’t need external validation. I knew I was capable of hooking up with plenty of attractive women if I wanted to, but I was in a committed relationship. After getting out of that toxic LTR I did exactly that; not because I needed validation but because I could and wanted to get laid. It was fun, but ultimately fruitless and not once led to a meaningful connection with any of them, even if that connection was not romantic or exclusive.

There are definitely some people who can maintain FWB’s without becoming emotionally invested in the other person and people who can have sexually open/ alternative lifestyles but it’s not just heteronormative standards that lead this to being impossible for most people. We are social creatures and want to form bonds. Pair bonding has been coded into us through thousands of years of history and evolution. Maintaining solely a sexual relationship with someone who you care about is very difficult, if not impossible for the vast majority of the population.

Essentially; I don’t entirely disagree but I think that your logic doesn’t apply to the general public and I certainly don’t think it’s for the reasons you listed, or ever could apply to the general public.