In countries like Australia, Canada, and the United States it's very often that cities are built with cars as a first priority, walking/biking as a distant second, and if you're lucky you might get an underfunded and undeveloped tram or subway network.

Car infrastructure is expensive to maintain compared to other modes of transit based on the volume of people that can be moved. Cars also take up more space than other forms of transit like bikes do, and they take up proportionally more space when compared to public transit like busses, trams, and trains.

Car centred development emphases wide roads and vast parking lots that rob space from what could be actual development.

Car dependent infrastructure (and cars) have varied health and safety problems associated with it. Since pedestrians usually have to interact with roads meant for cars and with cars being heavy beasts moving at high speeds, many people get seriously injured if not killed by them. Cars also contribute greatly to environmental pollution in a way that even other forms of gas-based public transit (such as busses) cannot considering economy of scale. Audio pollution is also a less talked about issue that these vehicles create, which can cause anxiety and stress. If you're like me and have sensory processing issues, than the noise of these vehicles can be unbearable without ear protection.

Driving a car has little actual benefits for you. Inside public transit, you can get some work done while making your way to your destination. Biking contributes to often much needed exercise that is lacking in car centric areas. Humans were also built to walk, and walking a few kilometres every day is actually pretty good for you. You don't get those kind of benefits from driving a car.

Cars themselves are also pretty expensive compared to public transit, a bike, or obviously walking. Many people would be able to save a great amount of money on anything from gas/electricity needed to power the car, to the maintenance needed to perform on the car.

I'm not saying that we should eliminate all cars, they do serve a purpose. It's just that purpose isn't mass transit. In countries where urban development is more sensible, such as Japan or the Netherlands a fairly low amount of people or own a car drive because the alternatives are better 95% of the time.

These countries do have car infrastructure, and infact driving is a better experience in these countries. You are less likely to run into traffic jams, there is more money to maintain car infrastructure (because it's a huge expenditure in car dependent areas) so the quality of such infrastructure is usually superior, and the people that drive are doing so more often because they actually like driving rather than being forced to drive.

Each form of transit has it's own strengths and weaknesses, and a good city will see that and develop with each form of transit in it's best element.