Serious Question: Do they all use it for adult content? I've never used OF but see the porn/adult references all the time so I assumed that is all it was (obviously not it seems?)
I am sure someone is going to come up with silly edge case examples, but OnlyFans is for porn, and anyone else who says otherwise is trying to spin you.
Exploiting this, you get Cunningham's Law: "the best way to get the right answer on the internet is not to ask a question; it's to post the wrong answer."
Better: any made up story may become true eventually.
I've experienced this first hand. I was a compulsive liar in primary school and one time I told my friends that I saw a webcomic that had this gimmick that every panel ended with the phrase <insert topic> is EVIL(BAD) ("Złe/zły/zła" in Polish).
