It would seem that way, but not necessarily. It could be as simple as technologies that exist(ed) and were regulated out of existence. It could be increased laziness/lower creativity... there are multiple variations on bikes/scooters there that each look as though they were put together by different minds, which implies that people were better able to understand machinery to a greater extent than people today. Let's say you were to make one of those bikes; you either buy the parts separately (frame, motor, gears, chains, etc) and piece them together or you'd need to buy the materials in a closer to raw form and either possess or have access to welding gear, etc. the investment in tools can relatively quickly get into the 10's of thousands of dollars.