Is there any game to earn money?

I'm curious, is there any game out there that actually allows you to earn money? I've heard rumors about some sort of crypto-based gaming platforms where players can win real cash prizes, but I'm not sure if they're legitimate or just a hoax. Do you know of any legitimate games where I can potentially earn some extra income? I'm not expecting to quit my day job, but it would be nice to have a bit of fun while potentially making some money on the side. Can you enlighten me on this topic?