Just because something is old does not mean it is a bad idea. By the way, bicycles were first developed in the 19th century (not 18th) and have been continuously improved since then. And motor vehicles are not much newer, anyway. The Benz Patent Motor Car was sold in the 1880s. For comparison, the most popular type of bike sold today, the "safety bike" became popular in the late 1880s.
https://en.wikipedia.org/wiki/History_of_the_bicycle
https://en.wikipedia.org/wiki/Safety_bicycle
I've explained cycling to high-tech types as taking advantage of the literal nanotechnology the human body uses. Bikes make use of the human body much more than cars in my view.
I never said bikes are better in every way, or even more efficient. Actually, I think a well designed motor vehicle could easily beat a bike in efficiency, particularly for common diets, but it would be smaller like a bike. E.g., a motorcycle could be better.
My argument was that old technologies aren't necessarily bad and that motor vehicles are nearly as old as bikes, so the age argument also applies to cars. I don't disagree that cars have benefits.
Newer is not inherently better.