It is a common understanding that owning your own vehicle is best in all circumstances. But the truth is that many people in dense downtown areas are opting to travel by taxi. Some may have a private vehicle but find traffic and parking costs prohibitively expensive. As a result, they drive to work by car but any other trips made locally such as social calls and shopping are done by cab.
There is also a growing group of urban residents who simply don’t own a vehicle. Working locally allows them to commute and any other trips are better done from the comfort and safety of the back seat.
Living without the costs of fuel, parking and insurance and only paying for the rides you need is cheaper by far. And naturally there are no-brainer situations such as a trip to the airport where a cab is the only sensible option