Oh, no doubt. But there's pretty strong circumstantial evidence when an artist starts out producing nothing but SFW content and gradually slides into NSFW until that's all they do. And I'm not including tasteful art that'd get a NSFW label for nudity in that, either. Just a wee bit different from the obvious-horny-teenager sorts that begin, carry, and conclude their foray into creative writing with stories that are functionally excuse-plots which exist for the sole purpose of letting their characters of choice boink.
The opposite happens plenty, too, though. Folks that transition into SFW and then basically can't share stuff they enjoy making (i.e. nsfw stuff) anymore because of the effect it would have on the consumption of their other material. Or start sfw and then don't really get to expand because of similar concerns. Certainly some folks (let themselves) get drug down to the lowest common denominator, but that's everywhere, and not even remotely unusually prolific when it comes to matters of lasciviousness, at least from what I've noticed over the last couple decades.
That's the main problem with it for me. Porn is the visual equivalent of mindless lemon fics/supermarket bodice-rippers, goofy unrealistic shit that's more disturbing than arousing.
... it can be, anyway. There's also plenty that's... not. Stuff that's amusing, touching, involve pretty impressive character interaction or settings, so on and so forth. Probably less often with the live action stuff, but we've been talking th'other sort. It's a genre of creative work that's like any other, just one with somewhat different goals, methods, and so on -- more freedom in some ways, less in others. There's a lot of potential in the incitement of arousal (or even just the exploration of sexual situations) that gets explored, and doesn't quite have equivalents in material that's more... tame. Whole other set of angles and focuses and expressions and so on that just don't get touched on in other venues much, if at all.
Though sometimes being goofy and unrealistic is half the point, heh. Ain't nothin' wrong with that so long as someone's (preferably both creator and audience, but it can be one or the other, too) enjoying it. Fun is fun, et al. And there's a fair amount out there that's pretty easy to enjoy even if you're not specifically aroused by it at that moment in time. At least if you're not (intentionally or otherwise) trying to sabotage your own enjoyment