That’s why it’s called a “natural-occuring” Ponzi, not an overt Ponzi. That’s how Bitcoin started to have surging value, as a “Ponzi”. For it to pay profit to a holder for higher value, newer investors must enter the system and buy them from those holders. BUT, like Gold, it stopped being a “Ponzi” when it was started to be used as currency in the dark markets, creating a circular economy.
Before bitcoin was started to be used as a currency of dark markets, it had no market value, and couldn't give any profit to early holders because newer investors had no reason to invest in something with no market value. Moreover, even if they wanted to invest in bitcoin, they couldn't do it anyway because early adopters saw no reason to "sell" their bitcoin. Those who wished to obtain bitcoin didn't buy it but rather invested their money to buy hardware with which to acquire useless (priceless) bitcoin. It was but an indirect purchase that didn't involve other people except for the miner himself. No one could have predicted that bitcoin would transform into something that has a non-zero value, but the fact that did happen doesn't make early adopters somehow look like nefarious creators of Ponzi schemes. This is an example of the natural-occurring evolution of money when it starts its journey as being collectible/commodity and ends up being used as a universal unit of measurement.