We don't have flying cars for a number of reasons. Efficiency, reliability, user safety, public safety, supporting infrastructure (where to land), new complex regulatory requirements. eg, what about cars flying over your house.
That said, see my post above about why Elon Musk is unwittingly responsible for flying cars. Spoiler: electric cars threaten fossil fuel industry which will push for flying cars that use even more fuel and won't be electric any time soon.
And they have the lobbying power to make it happen despite all of the logical reasons why we don't have flying cars now.