I think that the real problem is "opportunity cost". People can make money on only fans now, but later find out that their career prospects have decreased because in other industries people would judge them for what they did at only fans (even if their performance at the job doesn't change by that).
And since people grow old, the "only fans"' income might decrease over time in favor of "new" and younger women.
If they stop working at other jobs that they can put on the CV, and that benefit from work experience, the blow to their earning capability would be even worse in the long term.
I guess what I'm trying to say is that for only fans to be a valid option/choice, they need to make enough to invest in a business or other assets that would give them income in the future. Otherwise it is just a way to make ends that might make things more difficult in the future. Which I don't blame people for taking, we do the best we can with what we have, but not as interesting as some people try to say it is.
But that is just my take.