By that definition any stock that doesn't pay a dividend is a pyramid scheme. Of course, if you believe it has no value whatsoever, then anything can be seen as a pyramid scheme.
I was going to make a similar comparison. I casually invest and trade crypto and stocks, I have been burnt when early adopters sell off after a company releases a good announcement. After a good announcement, new investors will buy and early investors sell off at their expense, I've seen this result in a stock losing more than 40-50% of it's price, sometimes it will never recover. I think both markets are affected by similar forces.