It's pretty hard to be isolated in a world of six billion people. The more key question is the probability of coordinating with any randomly selected person on a rationalist topic of fixed difficulty, and the total size of the community available to support some number of institutions.

To put it bluntly, if you built the ideal rationalist institution that requires one million supporters, you'd be in trouble because the 99.98th percentile of rationality is not adequate to support it (and also such rationalists may have other demands on their time).

But if you can build institutions that grow starting from small groups even in a not-previously-friendly environment, or upgrade rationalists starting from the 98th percentile to what we would currently regard as much higher levels, then odds look better for such institutions.

We both want to live in a friendly world with lots of high-grade rationalists and excellent institutions with good tests and good incentives, but I don't think I already live there.