A flurry of insights that either dies out or expands exponentially doesn't seem like a very good description of how human minds work, and I don't think it would describe an AGI well either.

That's how technological evolution works, though. If you're in olden-days-Tasmania, you get devolution. Otherwise, you get progress. There's a threshold effect involved. We have to reproduce the progress seen in cultural evolution - not just make a mind.