Never said BTC was ponzi, I said Kairos was. BTC is different monetary scheme, with strong elements of pyramid. There are several ways to prove BTC is a fraud, the simplest to understand is the mining part.
Critically important: mining is the backbone of BTC product right? Miners do validating and keeping history of transactions right? They get a chance to be awarded with coin in return, right? But release rate of coins is diminishing in exponential rate. That could be possible, et number of transactions dropped in such a pace too, but that is not the case. If BTC was healthy product, the need for calculations would rise over period of time, not shrink!!
The number of released coins is diminishing due to a number of reasons. One of them are halvings that reduce block rewards. There's also increasing difficulty due to more powerful miners being released. POW has its downsides, no system is perfect, but I can't see any signs of a ponzi scheme in the way BTC is being mined. I'ts actually pretty healthy when you realize that it's able to regulate itself by adjusting the difficulty based on hash power.
Now, absence of real product is a clear sign or scheme.
Absence of a product? Really? Then what are you buying when you're paying your internet bill? The company that you're paying doesn't produce anything, unlike a power company that produces electricity and maintains the network. Telephone cables don't get hit by lightnings and storms and you don't need power meters, breaker boxes and transformers everywhere. You're buying the permission to use the global network. If this isn't a real product, then bitcoin aso isn't, but both have value and people are willing to pay for both. Does that make internet companies scams? Does that make a domain you pay for a part of a scheme? Let's be real, this is 21st century, you don't have to hold something in your hand to know that it exists and has value.