Ponzi schemes are per definition a scam and puts legitimate sites in this section in a bad light. Hopefully, the mods here can take action and at least move these sites into another section.
Why are these a scam?
Because there's no pre-arranged set of rules, no stated house edge, no provable fairness, no nothing. "I'll just steal all your money whenever I feel like it" isn't even a numbers racket, it's just a scam.
Even outright sucker games like keno at a casino have a measurable house edge and a set of rules even a punter can understand.
Is this seriously beyond your comprehension? Have you considered getting help?