This isn't a new practice, but the stakes are higher.
It used to be that you could write to "celebrities" for an autograph. You hoped it was the celebrity who signed your thing and mailed it back, but in reality you knew it was probably their spouse or secretary. It wasn't honest, but it's not like they charged you money, and the emotional stakes were lower. They weren't pretending they were your buddy or your lover. They were just signing a thing for you.
With online adult media, there's that whole parasocial dynamic. The whole thing is made to make you feel like you have something like a personal connection with the model.
I wonder if there's a way to do it ethically, while also keeping it fun for the subscriber.
Like honestly the answer might just be transparency. ex: "Sometimes my assistant XYZ helps me answer the huge volume of messages I get. We'll always sign our replies with the name of the person who actually wrote the reply." etc.