I’ve heard that adage about the porn industry pushing innovation, but I’m not sure it’s entirely true. Like, I believe “the world standardized on VHS because the porn industry did” is outright false.
Hosting porn brings down a whole load of legal scrutiny onto your service. In some places in the world it’s outright illegal or the effort it takes to do it within the law is so great that it’s not worth doing. Several instances don’t want to even attempt it. Instances that do probably need to specialize in the kind of attention that sort of hosting requires.