True innovation takes a long time, sometimes months, years, decades or even centuries to make significant progress. Take glass for an example. Nobody really knows who first discovered it or how it was invented, but people suspect that maybe people found it at the site of a lightning strike, or that it was made accidentally under a fire on a beach somewhere. After that initial discovery, it was a long long time before people could reproduce it on purpose. A long time. Hundreds of years. But they got it. One experiment at a time, a little tweak here, a twist of that there until it became an art form. Artistic expression in glass has been discovered in ancient Egypt, ancient China, Mesopotamia, India and other parts of the world that date to 1500 BC and before. It wasn't until AD 100 or so that clear glass emerged in the area of Alexandria during the Roman empire and could be utilized, although rudely, for window glass.
Wood frames for windows emerged somewhat as painstakingly as glass did, with the biggest advancements arriving contemporary with metal tooling. Mortise and tenon joints, used to connect wood perpendicularly, have been discovered dating back as far as 7000 years. Suffice it to say that in the time since those earliest discoveries, mankind has pretty much mastered that joint.
By the time railroads were making their way across North America, tool making and glass making were somewhat standardized, as well as the mortise and tenon joint. Note that the mortise and tenon joint had not significantly changed in thousands of years. Why? Innovation is really hard and takes a long long time