That only works if you have a SO, which isn't even necessarily what everyone wants.

Well sex kind of inherently requires an SO (however you choose to define "significant"), and porn inherently has to do with sex. Masturbation is trying to be your own SO, but sex inherently is a two-person job. I know these things are controversial these days, but they're pretty obvious and self-evident if you ignore recent ideologies and politics.

Ignoring your distasteful name for a moment; you have a very black-and-white view. 2 person job? Said who? 1 person sex, or 3 person sex, or more... Who says 2 is the only or even the best way?

The physical nature of human beings: a single penis fits into a single vagina, and that's how babies are made. It takes exactly two people for this to work. Sex can be done in other ways but this is the magic formula for sex to make a baby, and making babies seems to be the primary purpose of sex within nature. And my name isn't meant to be tasteful, it's meant to be honest. I committed the crime of public indecency and am a sex offender for life.

I think this is a very uninformed opinion. If what you said was true, there is no logical reason for why humans would have sex while they are already pregnant.

I won't even point out all the reasons your argument doesn't make sense, because it's clear you haven't thought about what it would mean if what you said was true. It just doesn't match up to real human behavior.