If you look up the user demographics, you'll notice an obvious problem: The demographics do not include the number of users under 18.
https://techreport.com/statistics/software-web/onlyfans-stat...
Some may say: well that's because you have to be 18 to use the site. But that's not true. Anyone can signup for onlyfans without entering their age. Onlyfans only does age verification for creators.
If you think this site isn't primarily being used by teenagers, then I have a bridge to sell you.
What do you mean by "preys on"? Teenage boys seek out porn, is normal. There's nothing magical about this type of porn. If they are breaking the ToS and committing credit card fraud, who's at fault?