> If such conventional bike cost 100 dollars and can last 20 years then [$20] cardboard bike must last at least 4 years to be competitive.
No. We're talking about poor people. A $20 bike that lasts less than 4 years is much more attractive for many people than a $100 bike that lasts 20 years because they don't have $100 to spend on a bike.
> And people with unstable income prefer long lasting solutions because there is probability that there will be no money in future to buy replacement.
Prefer? Sure, but I think you're overlooking the fact that poor people often can't afford that luxury (sometimes due to their own poor decision making resulting in a vicious cycle but that's still the reality).
No. We're talking about poor people. A $20 bike that lasts less than 4 years is much more attractive for many people than a $100 bike that lasts 20 years because they don't have $100 to spend on a bike.
> And people with unstable income prefer long lasting solutions because there is probability that there will be no money in future to buy replacement.
Prefer? Sure, but I think you're overlooking the fact that poor people often can't afford that luxury (sometimes due to their own poor decision making resulting in a vicious cycle but that's still the reality).