"Paying for porn is stupid. But I just have to have everything of this specific person or fetish, so I'll pay, scrape, then chargeback."
I'm skeptical that it's a lot of kids because I feel like finding free porn is pretty darn easy if you try. Why would they ever bother with all the friction that goes with charging their parents CC?
(Just checked, the top three Googles for "free porn" are sites with a lifetime of free porn)
Porn is much more about revealed preferences in isolation.
Just a FYI.
They own Brazzers, Digital Playground, Reality Kings, Twistys, Babes, Sean Cody and Men.com for production studios.
There are thousands of tube sites, two of which have more traffic than those mentioned above. There are hundreds of porn studios, many which are more popular than those listed above.
I download a lot of that content too (sans the chargeback). I like to have it available locally, even when the internet is down, when the site decides to take a particular video down for whatever reason, or even when my account expires. And paying for it makes it just a little more likely they will continue to produce more of it in the future.