The known problems to them is that most coins are going to have less value in every bear market assuming you really meant play to earn games. Looking at the Axie, its price was more than $100 back in the bull run, and then look at it now.

There are tons of them these days on every platform and they'll be hyped next year as we are approaching halving. More investors and players will come too but if they are not traders, they will lose their money.