people are in it voluntarily

That’s an assumption. Plenty of “amateur” producers are still in bad situations. There was the recent OF scandal of pimps forcing girls to produce content. There’s private recordings that were made in good faith and later publicly distributed (i.e. revenge porn.) There’s women that posted on Reddit when they were 19, and now that they’re 25 they can’t seem to scrub the pictures off the net. If you’re looking at a real live person, there’s a non-zero chance that they don’t love that you’re looking.

I’m not saying don’t look at pornography. Just don’t take it for granted that anything you find was ethically sourced. The only assuredly ethical choice for cranking your hog is what the real freaks post to AO3.