Richard, that's a good point . . . - but then what should I believe about markets and investments, conditioned on scientific and technological progress having been slower than expected?

Well, if you have been misled into believing that scientific progress having been slower than expected entails economic production falling or stagnating, then you will tend to have assigned too high a value to investment strategies or hedging strategies that bet on the performance of the economy as a whole (e.g., shorting index funds). So, perhaps look for more specific bets. E.g., sell short shares in companies that produce "emergence engines" or "consciousness capacitors" or some other output demand for which will fall if progress stagnates in the area of science under discussion.