maybe the average European bike, which is like this one [1], but much older.

Maybe you shouldn't assume your friends represent a representative sample.

[1] https://en.wikipedia.org/wiki/Bicycle#/media/File:Left_side_...

> Maintaining a bike is cheaper and easier than maintaining a car.

but very few do it, given that they are not forced to keep it functional, unlike here, where I live, where your car has to pass a state mandated safety inspection every 2 years.