Maybe you are right but the actual facts are that even outside OF there are underage female prostitutes that do it for money or the latest bag from some high end brand and often are prey of some predator. Only difference is that off-line prostitution is harder to find.
OF is only folowing what it is happening in the real life, making it easier obviously, but it don't create any new dynamic.

The facts could be there, but people have good reason to be reluctant to go looking for them. Kids are dumb. They do stupid things all the time when there’s nobody there to tell them how stupid and dangerous it is. Their brains soak up as much as possible, and when they hit puberty, their brains start sloughing off what it thinks is excess, and suddenly they think it’s a good idea to ride a bike off a waterfall or some shit. Secretly opening an onlyfans for stupid easy money from pervs seems hardly a stretch to me if you knew you could avoid being caught.