I've seen many blog posts describing bitcoin as a ponzi scheme, but looking at the current inflation of fiat it now looks like a Ponzi. Don't know who is the beneficiary in this kind of fiat Ponzi. The earlier generation had enough to buy with few amounts that can't buy anything reasonable today. I also saw Elon in a tweet saying or calling fiat a Ponzi scheme. People suffer to get fiat and lose it on high food prices and products. In a Ponzi, everyone end up losing money, same with fiat. A good number of people around me complain of not being able to purchase product with a fair sum of money they feel is big.
I think governments are the ones that make money out of it because they release funds into circulation that are pegged to some other form of valuable asset like gold or dollars. Which means if they are releasing 100k PKR, which is my local currency, then it means it is backed by the same amount of gold that can be bought with 100k PKR, and when that money is given to the public or to some single individual, the amount will go up or decrease due to inflation, but due to the inflation, that gold, which they still have, will be making them money.
And if the fiat system is really manipulative, then they might buy gold or dollars after issuing the local currency, but only in a manipulative way because, literally, that's not possible.
At the end, I don't think Fiat is really a Ponzi scheme because Fiat is not something new and it has been among us from the very start, and it really made our lives easier. At first, we had to give some kind of product or service in exchange for one, but now I don't have to get a skill that can help others so others can exchange it with me. I can simply give them Fiat to make them do their work, and they can pay me to do their job.