While I would agree with you about the problem of ecosystem, I would not go that far to call it a ponzi. By the book, it can't be as long there is at least some percentage of quality content produced having some "market" value outside the closed ecosystem that could be represented in fiat, therefore, there is a production mechanism to deliver "Surplus Value" (We need to put Marxist theory into play here due to anarchistic setup of the ecosystem). Is it overvalued - I would say yes (at the levels you are talking about), but if you analyze overall quality of newcomers content that earns 1SBD at max, I would say that would be far bellow the real market value (the price of the appropriate quality content you would buy from content writers). Since significant number of people do engage in creating content (a product) at the entry level of ecosystem, I would say there is a healthy potential of correction of the platform. Where it starts to look like a ponzi, is devaluation of entry level to support unjustified earning on top levels. In typical ponzi, surplus value is never produced, rather pumped externally. This would be more a representation of neoliberal capitalism combined with Anarcho-capitalism in small. While the system will crush itself unless the problems you mentioned are solved, at one point it would become crucial to solve to protect the investment by these who made most of profit. Since the modern society is living by the very similar principles of economy at the current development stage - it's hard to predict what would happen. We never had a microsystem based on combination of Anarcho-capitalism, Neoliberal capitalism, and certain types of Communism, governed by the Anarchy and direct democracy with corporate capitalism a-like "share weight" type of voting and some surplus value (content) produced that has it's fiat backed value :)

I would not go into predicting an outcome of that spaghetti :) It would be much harder then predicting world economy trends on the long run.

But one is for sure - every economy that implements even small portion of Anarchistic or Communistic principles, require high level of consciousness. I very doubt we are at that stage yet, and as a result we see the negative phenomenas you mentioned, and therefore are Utopian. Still, it's not as simple as ponzi.