Roots of Progress has an interesting deep dive on why it took so long for a (relatively) simple invention of the bicycle, even in a time when the principles of a bicycle’s components were well understood for a long time. There’s an interesting inventory of potential hypotheses about why it took until the late 1800s.
Early iterations of human-powered transport looked like inventors trying to replicate the carriage, with devices that looked like “horseless carriages”, someone providing power, another person steering. The first breakthrough toward something that looked like a modern bicycle (at least in form factor) was from German inventor Karl von Drais, modeling his design on the horse rather than the carraige:
The key insight was to stop trying to build a mechanical carriage, and instead build something more like a mechanical horse. This step was taken by the aforementioned Karl von Drais in the early 1800s. Drais was an aristocrat; he held a position as forest master in Baden that is said to have given him free time to tinker. His first attempts, beginning in 1813, were four-wheeled carriages like their predecessors, and like them failed to gain the support of authorities.
It seems cultural and economic factors make the most sense as explanations, versus technological or environmental ones:
In light of this, I think the deepest explanation is in general economic and cultural factors. Regarding economic factors, it seems that there needs to be a certain level of surplus to support the culture-wide research and development effort that creates inventions.
Like most breakthroughs viewed with the advantage of hindsight (and in this case 150 years of it), the invention seems so obvious we struggle to imagine why the people of the 18th or 19th centuries wouldn’t have worked on the problem. Combine the non-obviousness with a lack of cultural motivation and an unfriendly economic environment, and it’s not surprising it took so long.