It’s not really a ponzi scheme when it comes to cryptocoin because they just keep minting more. They are literally printing money. So they don’t need a source of money. This isn’t me advocating for such games at all though. They are usually trash. I can see a world where something like WoW’s gold system is tied to a cryptocoin and thus the money you earn in WoW gains more direct real-world value. Of course, it’s something like 0.00001 of a US dollar but it’s something.