Like others here have said, they are a combination of get rich quick schemes and money laundering. They take the legalized gambling that is the stock markets to a whole new level. I also agree that the underlying concept of them is okay, but they’ve been exploited and hyped up to crazy levels.

If you want to play with crypto ‘investments’ and you have a bit of discretionary spending, you could try it. But just know it’s super-risky and built on a lot of bullshit. Personally I wouldn’t. I’ll stick to passively-managed index funds. They aren’t air-tight safe either, of course. But at least they are less prone to scams and risk.