This seems to be a pre 1900 view of the world, i.e. before relativity, quantum mechanics, complexity theory etc. [...] Early theorists believed that in science lay the promise of certainty. Built on a foundation of fact and constructed with objective and trustworthy tools, science produced knowledge. But science has also shown us that this knowledge will always be fundamentally incomplete and that a true understanding of the world is ultimately beyond our grasp.

Not really. Korzybski speaks strongly against the idea of certainty and how recent advances in science have shown it to be wrong. That's a substantial part of what Science&Sanity is about.

In summary, I think the issue is more of a perspectival one, i.e. with people’s maps.

Korzybski was the person who came up with using the word map in this way.