I've been following a bunch of girls for a while, most of them free accounts or free trials. Been scammed a few times, and as it's become more and more obvious it's not the girl DM'ing, I've made fewer purchases where I didn't know what I was getting. I even will play along when they start that "free sexting talk," but the minute they put up the overpriced PPV, I leave the chat. I have been following one girl who is somewhat local, and from what I can tell, she still runs her own page - DMs aren't answerd right away, we've chatted about real life things a few times, and she's definitely NOT on 24/7. She does spam a lot, but in this case, other creators pay her to promote them, so she gets extra money I believe. While this can be annoying, I can at least respect it because she's doing it to make extra $$, especially considering her page is free.
The one porn star who definitely isn't using an agency IMO is Crystal Clark. Yes, she posts a ton of professional PPV vids, but when it came to sexting, the proof was in how she did it. She only has certain slots available, and once they're filled, that's it until the next time. I sent her a message asking if, on top of the fee, there'd be unlocks with increasing prices. Not only was she happy to answer me (and actually made it a point to say that she doesn't agree with that strategy), but she did it in a video message. When sexting, that was also how she did it. I'd type my part, and she would respond with a video of herself, making it clear that we were actually interacting. If more models would do this, I think they would be more successful. Killielou and Kate Shelor are two others who I believe are also doing it all themselves.