> people don't want to replace their cars with them. Why? It is an unsolvable problem
Unsolvable?
You aren't allowed to fly them at night, or over any populated area. They can't have more than a single seat. They have severe weight restrictions that mean you can't take much in them besides yourself. (Note: the previous few sentences describe the US regulations; other jurisdictions are different but all have similar kinds of restriction.) You can only travel to and from places that have a substantial length of runway for takeoff and landing.
Do you really find it difficult to imagine why someone might not find an ultralight aircraft a suitable replacement for their car?
Unsolvable?
You aren't allowed to fly them at night, or over any populated area. They can't have more than a single seat. They have severe weight restrictions that mean you can't take much in them besides yourself. (Note: the previous few sentences describe the US regulations; other jurisdictions are different but all have similar kinds of restriction.) You can only travel to and from places that have a substantial length of runway for takeoff and landing.
Do you really find it difficult to imagine why someone might not find an ultralight aircraft a suitable replacement for their car?