Not universally-true. Contrived scarcity is bullshit and reduces enjoyment for me.

I don't subscribe to monogamy or closed relationships. Regularlly, I'm with 3 bi/pan females who would all eagerly have my children whenever I wanted. They sleep around primarily with women, as do I. It's way more enjoyable than the "waiting until marriage"-types and virgins who I actively avoid because they're dull.