Was it divine intervention, or something else that led these masters to create the unimaginable in their times?
I'm just asking the questions since I don't really know......I'm sure you do tho
Why so testy?
I can guess with high accuracy...
Geniuses occur frequently enough in the population; but, their social conditions contribute to their ability to innovate. If genius is recognized, they are seldom supported in a way that allows them to develop radical solutions. Any person that must labor in order to survive will have less opportunity to work human miracles. A genius from a rich family is more likely to have time to ponder esoteric ideas. Time would allow for a higher education and workbench activities to develop ideas.
A genius must also be a self-driven person, one of purpose and eager fulfillment. They need tenacity in order to create outside normal expectations. Edison tried nearly 10,000 ways to make electric light before he was able to narrow down on workable designs. I suspect all of the inventions listed in the article also went through extended periods of time as the designs were perfected.
I figure conversation is more productive than a "blow off".
The inventions and technology that came to be in the late 1700s, through the 1800s, and especially the 1900s are far more radical than those of Medieval times. While your premise is true that few today could make a trebuchet, it is a certainty that the couldn't make a digital computer from scratch either.
For example, the Periodic Table of the Elements had a more profound affect than the trebuchet.