IMHO, all crypto schemes are ponzi schemes and ought to be illegal. They are not currencies of legitimate nations. They thus do not produce either a product nor a service. Because they do not produce at all, they can only leave debt to later investors, which is what a ponzi scheme is. Additionally, crypto costs a fortune in electricity to mine, and is contributing hugely to global warming, if you believe in that sort of thing.
Don't sell your real money for fake money. Sooner or later someone has to get left holding the bag and it could be you.