It's the incel delusion that if you just acquire a girlfriend and/or lose your virginity all your crippling social issues and anxiety goes away. You wake up as Chad the next morning.
It... does help a lot. I think there are a lot of young adults out there who go through life with dead hearts thinking that they're not worth anything and that intimacy is a hollywood trope. Then you experience it both physically and emotionally, and the world really isn't the same again.
Plus, if you go through life thinking you're not worth anything, then you will develop social ticks like anxiety, stammers, OCD, you name it. Hell, in my case, going to the gym did more for me than years of psychiatry ever did.