OnlyFans is a temporary fad that will quickly go away as more people start doing it. It used to be that in the early days of YouTube you could make insane levels of money just by playing games. The same applies to Twitch and the live-streaming services, or even drop-shipping Chinese goods with social media advertising. All the success you see on these platforms is because the creators are exploiting a temporary gap in the market - more demand than supply - but little actual skill is involved and the market will re-adjust as more people start doing it (because very little skill is involved so pretty much anyone can do it).