Interestingly, Jules Verne (the then equivalent for technology- and exploration-worshipping hard sci-fi authors of today) was reaching the height of his output

Interestingly, Jules Verne (the then equivalent for technology- and exploration-worshipping hard sci-fi authors of today) was reaching the height of his output around that same decade (and the next), with some of his most significant works having been already published in the 15 years preceding it. It was definitely an age of great enthusiasm about technology and progress, and I think Verne's books capture that energy pretty well. If the 1880s were the miraculous decade in terms of technological breakthroughs, the first 3 or 4 decades of the 20th century were a radical fracture in terms of fundamental thinking across the whole culture: Einstein, Godel, quantum physics, post-modernism, dadaism, Picasso, Joyce's Ulysses. I think we have yet to fully comprehend the magnitude of that tectonic shift in how we think of and understand... well... everything. It was massive and it touched everything. And there's a common thread to that whole massive change. If I had to summarize it in one word, it would be 'relativity'. We've stopped thinking in absolute terms, and started to understand the value and validity and truth of the many different points of view. A century later, that kind of understanding is still percolating into politics, social mores, and daily life.