Bitcoin is nothing new. See Rai stones: https://en.m.wikipedia.org/wiki/Rai_stones

It's the people invested in it that gives it value. Just like fiat, gold, art, stamps, useless antiques, etc. As long as it has value to someone, then it has value. I can't see it disappearing anytime soon. Yes, it might fall and rise in value but to disappear like any other Ponzi scheme? Don't hold your breath. Bitcoin is more than a decade old now. It will be the longest running "Ponzi" scheme. Be back in a decade to say I told you so. Bye!