Maybe it is worth repeating here:

I think the reason it took so long to discover "the map is not the territory" is that it is applied atheism. To a theist, the map in god's mind caused the territory to happen, so that map is even more real than the territory. And every human map is as accurate as it approaches the primordial divine map (or Platonic Forms), the fact that it also happens to predict the terrain merely being a nice bonus. Even Einstein seems to have believed something like this.

To invent "the map is not the territory" you not only need to be an atheist, you need to be an experienced, confident atheist who can figure out what follows from it, and have balls/ovaries of steel to challenge about one and half millenia of quasi-Platonic intellectual tradition of philosophy and science which was about looking for the primordial map.

This becomes intuitively obvious if you think about something artificial, like a house. I make a design of a living room 4m by 5m accross and draw a blueprint. Based on this blueprint, a hundred houses are built, but as bricklayers are not surgically precise and kinda drunk, one house will have a 3.99m x 5.01m living room, another one 4.02m x 4.99m and so on. A century later the town crumbles and a thousand year after that archeologists try to dig it out. What are they going to do? Just measure every room and leave it at that, or rather consider these variously sized rooms are actually 4m x 5m rooms, just inaccurately built? Will they try to figure out the idea, the blueprint behind it, the primordial map that created the terrain? The 4m x 5m map they themselves draw will not be accurate to the terrain, but it is the terrain that they will consider inaccurately implemented, not the map, they will think they have found the primordial map, blueprint, that was inaccurately followed (correctly). And that is largely how theistic science worked. We assumed there is a primordial map. We assumed reality has a blueprint, and we tried to find the blueprint, not simply figuring out reality. Saying the map is not the terrain is another way of saying there is no primordial blueprint, no creator god.

This is why it took so long IMHO.