In other words, when Haber process was discovered, the question was NOT "wouldn't it be great if we could produce fertilizer out of air?". The question was, "We know the air is full of substance that makes fertilizer. How can we make that happen?"
Or, alternatively, when nitrogen was discovered, nobody said "We paved road for making fertilizer out of air!" It was probably something like "How weird, air is full of this strange stuff that makes animals suffocate." And apparently its discoverer went on to call it "noxious air".
Honestly, I can't think of any important scientific discovery that was accompanied by "This is great! Think what it could do for civilization!"
[1] https://en.wikipedia.org/wiki/History_of_the_Haber_process
Radioactivity.
"We can what down Ook's village?"
And, I mean, we can't get energy just by digging in the ground. We didn't just poof, start flying over the ocean. We don't produce fertilizer just poof out of the air.
Also: we knew before the Wright brothers that heavier-than-air flight was possible (birds). We didn't go from nothing to oil-fired modern powerplants in one step. If someone had claimed to generate electricity from something random in the ground -- even inefficiently -- without piggybacking on centuries of preexisting power generation technology, I'd probably have been skeptical. And my skepticism would probably have been justified.
I didn't say anything about AI or space elevators.
I'm not skeptical about hot fusion the way in skeptical about cold fusion.
I get that people are more likely to exaggerate the likelihood of success of some technology if it seems extremely promising, and thus one should be more skeptical of those... But given all the other information available, that's a very weak proxy. You can make your own opinion by looking at the science.