These girls are making a killing from men like these
I think for a lot of men leaving the safety of their homes, their neighborhood and the place they grew up in with the familiar faces is a difficult thing. You would have to be a adventurous, and also be a certain personality type to step out of your comfort zone, and actually meet people. There is also some baggage from upbringing, religious & family background, and belief systems that keep most men from venturing out of their comfort zone. They can rationalize this virtual interaction, and also get some excitement from a break in the monotony of their lives. Before we had OF, there were phone sex hotlines, where a lot of men racked up huge bills to be talking to someone pretending to be a beautiful lady. And porn is I think similar to OF - except that OF has the one on one human connection that we all desire, and hence the popularity. As far as folks paying for porn and OF, I think once they have discovered something that they can enjoy, they will stick to it - in the same way that they will stay within the confines of the safety of their homes. And this could also be true for the ladies - you would have to be adventurous and a confident person to be a SP.
I think though that competition is fierce, loyalty can be fleeting, and the overhead costs with the time commitment can be big. And like any other social media phenomenons like Facebook, Snap, twitter etc. there will an initial upward curve, then a flattening of the curve, and later a downward slope when folks figure out that the virtual world is boring compared to real life.