That isn’t true - I think the people who don’t make it are massively skilled. It’s not random in the sense it’s just selecting randomly from the population. It’s random in the sense that there are 100 elite content producers but at any given moment there is only space for 10 of them.
Stephen King has a massive leg up for already having built the inroads for having a successful book. I think if you give any elite, yet unknown writer, the same tools, editor, and publisher they would succeed. But to truly succeed from nothing may just depend on going to school with someone who became an editor, or the editor’s daughter showing them a TikTok. That’s what is meant by it’s largely random.