Not been to a porn site recently, or any media hosting site really? They all look exactly the same and offer the same features, so presumably they're already using some commodity off-the-shelf hosting platform for video, images, and live streams with sign-up and payment.

The actual barrier is very few performers are popular enough on their own to be able to afford hiring people who can run servers with this software for them, but the few who are often do have "club{NAME}.com" sites for their own exclusive content.