The Ponzi Scheme collapses when new participants dwindle or demand a payout, and the scammer disappears with the remaining funds. There's something my dad always tells me, " there is no such thing as something from nothing". Anyone that promises you a particular amount of BTC, and all you have to do is invest a particular amount or share their link to invite a given amount of people, that person is a scammer, and potential investors should avoid them at all cost.
Ponzi schemes are a major scam that should be avoided, especially in the crypto space. Their operations appear so real that you can't deny their methods of operation. I have fallen for such a scam before, but not in the crypto area because I was clueless about scam knowledge. This type of scam is directly and entirely directed towards bitcoin newbies, and they are easily duped. Those who come with the attitude of getting rich quick might easily exchange their bitcoins in the hopes of earning a better return from such Ponzi schemes, which would inevitably fail them.