The same was very much true for Babbage and the Difference Engine. If I remember correctly, the level of repeatable precision and quality needed to make something like that was simply well beyond what engineers could manage even at the height of the industrial revolution. In theory everything that Babbage was designing was technically possible at small scale, but simply couldn't be done on the scale he imagined.

If memory serves, even the London Science Museum's partial reconstruction in the 1980s was a massive challenge of engineering.