Same as actors and performers in any other era since the invention of recording and mass distribution, providing the possibility (inevitability) for incredible

Same as actors and performers in any other era since the invention of recording and mass distribution, providing the possibility (inevitability) for incredible amounts of money to concentrate (almost exclusively) to the very most successful at a given type of performance. You don't have to go through Hollywood (or whatever) anymore but it's still some happy intersection of luck + skill + hard-work (+ connections maybe) making it happen, with no two being sufficient nor all three being any guarantee, like there's always been, and there's still only a tiny (relative to global population) set of people who can be on top at any given time, no matter how high average quality rises. In the case of Ryan's World, he appears to have benefited from a mother willing to quit her job to be his producer very early in his channel's history, and also able to competently perform that job, well before it was clear it'd make serious money. So even for a 9-year-old there's the luck/connections thing playing a huge role in this being a viable possibility, let alone any kind of likely-to-succeed play.