What would it mean for SN to be flourishing?
If the reward mechanism has worked so well that it becomes a place where people who never create an account come to find articles/discussions on current events.
If the reward mechanism has worked so well that even articles/posts that are distinctly anti-bitcoin or anti-libertarian (or other topics that go against the current SN grain) receive lots of sats if they are the best anti-bitcoin or anti-libertarian articles.
To me, the distinct feature of SN is the reward mechanism. The number of sats on a post ought to be a signal of quality, not viewpoint. If this occurs, I believe we would observe the two characteristics above. The alternative is that people only give sats to posts that align with their worldview and SN will become an echo chamber, rewarding people for parroting the view of the day.
Here is my worry (this is a totally personal anecdote from past interactions many years ago), but in my experience there is a personality type that is attracted to austrian economics and libertarianism. If SN becomes a sounding board for those worldviews, I would consider SN a failed experiment.