Fatigue with World of Tomorrow=Impossible to believe in Progress (i.e., tired of the Enlightenment)
No ... the fatigue has to do with pragmatism rather than irrational optimism. We've seen how humanity progresses from the 1930s to the 2010s. What we have now is NOTHING like what was imagined in the 20h century. It's not that people are tired of rationality - rather it's the adherence
to reason and rationality (i.e. the ideals of the Enlightenment) that leads to fatigue over World of Tomorrow™ stories. At this point, we simply know better than to assume that technology will make everything better. We know that technology is a double-edged sword. We know that it has the potential to make our lives better, but that progress is not without cost or peril. That we must balance our progress with a responsibility to make sure we aren't overburdening either our society or our planet.
As such, Sci-Fi stories cannot simply be the escapist World of Tomorrow™ tales we saw in the 20th century. Fantasy can still be escapist. Which is a very popular draw for audience. And yet, Sci-Fi is still strongly represented in dystopian/post-apocalyptic tales, which present often deeply rational and reasonable perspectives on not just the benefits of technology, but also the perils and responsibilities of it.