Ah, but alchemy led to chemistry, metallurgy, physics, invention and many other unforeseen things, did it not?
I don’t think alchemy directly led to those technologies, but was a dead end. Alchemy’s contribution might have served to inspire, but others decided to abandon the approach and began making measurable observations and drawing conclusions from provable facts. A slow incremental process.
On that basis, I therefore propose that the fantastical may inspire technological advances, but the incremental, or even disruptive, advance of technology does not automatically lead to infinity.