This won't take off. Every computer on the planet and every smartphone on the planet..... Basically..... almost any device on the planet has storage, you got consoles, usb flash drives, tablets, Samsung smart fridges, desktops, laptops, Chromebooks, etc. With how much storage actually exists.... And every human on the planet with a device jumping in ... "hey it's free money"...... Difficulty would be so high you would be making like $1/day with 1PB. GPUs can get away with it because you don't have every single device on the planet mining because not every device has a GPU that can mine. GPUs are a lot more expensive which means not everyone can do it. There's a lot less so difficulty is lowered.