Additionally I would like to mention that especially in Europe, the illegal migration of people from war devastated nations in the last two decades has increased the criminality to unprecedented levels in history so that people in modern cities would prefer to use a private vehicle rather than public transport especially at night. Public transport requires a very advanced social awareness standard, a cultural level which is much costlier to build than the cost for the whole tonnes of steel, fuel, design and tyre that the private cars' availability costs! Otherwise public transport is by all means much cheaper and more environmentally friendly. Privacy, constant availability, comfort and autonomy in travel are the biggest advantages of the private car. The driving strain on the other hand and the limited room within the vehicle make the car less suitable for long distance travel compared to public transport. - Typical of mine, the answer to your question lies in the first and last lines; the rest is text dressing for the ones who like chatter :) -

There are various factors which define whether the use of a car is reasonable or not in a modern city. The most important factor amid those is population density. Often in very densely populated city centres the right of every individual to posess a private car and also have a place to park violates the harmonous flow of transport and also violates the right of the citizens to equally share the public space; imagine, a hundred of parked cars in the center of a densely built city like Athens in Greece deprives thousands pedestrians and disabled people of several hundred square meters of vital public area thus seriously deteriorating the citizens' life standard. In cities whith roomy architectural design as well as in suburban and rural areas the private car is a very comfortable and reasonable means of transport as long as the driver's behavior complies to a high standard of education and social awareness, a traffic culture which citizens enjoy in many cities and towns of central and northern Europe. Public transport on the other hand has an incredibly higher efficiency in respect to energy use, maintenance cost and urban area utilization but it requires a significantly higher social awareness so that people keep the public means of transport tidy and safe since anxiety and stress, once triggered in public, it becomes contagious.

It seems to me that the possession of a private car is very important for achieving a high standard lifestyle according to the 20th century western mentality. It offers irreplaceable comfort, autonomy of transport and advanced hygiene, especially for families with children. Starting from the early 20ies, the industrial production of the first automobile vehicles has offered to the wealthy citizens of that time the ability to travel autonomously on the sole cost of fuel; Before the first commercially availabe cars the individual citizen transport was mostly dependent on horse carts. After the second world war, in the early 50's the posession of a private car became a luxury which turned gradually more affordable for the lower income citizens, and by the 70's in most of the western world a car was a common object of personal property for the middle class. Cities in countries which designed and built cars as in USA and Germany were built in a layout which has offered plenty of room for the cars' volume and function; that is not true though for many other cities like Athens in Greece or probably Cairo in Egypt, cities whose residential and historic market areas have a mostly pedestrian design. In the first decade of the 21st century, after the peak of the "loan rush" in the developed countries, the posession of several cars per family became a typical standard in many countries while the capital of the automotive industry and oil trade surged to unprecedented levels. As a result, it didn't take long for the urban development in many countries to face the several problems that the excessnumber of cars has created. Lack of parking space, traffic jam in densely populated cities and high accident rate by improperly trained drivers started to show the limitations of car availability and use.

In my city public transport is unreliable and I would never use it at night.

In my city public transportation can either be faster or take a lot more time depending on where you're going. Also, it's not always as safe, you can get mugged. A private car allows you to carry stuff you couldn't other wise take with you when walking like say a big box, as well as get to and come from places in odd hours where there is no public transports running. So owning a car comes cheaper than using taxis often, for example. So even if you do own a car there will be a lot of times you will use the subway or buses, etc. It's not mutually exclusive. Here it's really normal for families to own multiple cars and it has nothing to do with status or socioeconomic positions. There are really cheap cars you can get on credit and people do that often, or buy used. Of course you see expensive ones as well but the point is the same. I think it's mostly convenience and safety.