Clickbait title. He didn't invent OnlyFans. He created a similar site which failed.
I think the punctuation makes it clear -- imagine "How I invented Facebook. In 2001." The full stop in the middle of the sentence breaks it and makes you realise he's speaking figuratively.
If the comma was strictly a pause for effect, sure. But it's grammatically correct and I wouldn't have ever read it the way you suggested.
You can't say you invented OnlyFans unless your product was named OnlyFans.