Play to earn is a scam, similar to Ponzi schemes. It only appears to work as long as gullible suckers keep putting in money. A sucker is born every minute, but (morality aside) companies still can't build a sustainable business model out of scamming them. Eventually they either run out of money, or catch on to the scam. Governments in some countries will probably also ban or restrict such schemes, thus making it difficult for them to operate within the legitimate economy.