
Hi OP, before the internet, phone sex existed where people would talk and role play their fantasies over the phone. Some even paid for it. Then once the internet started, AOL chat rooms had people basically make that into text. But back then it took a lot to get internet and a computer that was at home and not with us all the time. Thus there was a barrier and even geography for this.
Now there is all kinds of fringe groups out there justifying bad crazy things and these people come from that. They want to engage their fantasies with random strangers because it gives them high. It has some parallels to voyeurism. In the end it ain’t right but this is the bad side of the internet culture that even spills into real life.