Cars were, and to some extent, still are, a statement of wealth. Having a "horseless carriage" back when personal vehicles were called that, was an easy way to distinguish that you were a successful person. As time went on, this transformed into having the latest vehicle or vehicles of a specific brand or type, or that cost x amount of dollars... Many of these points are still true today, unfortunately.

Because of the status you would demonstrate having a vehicle, demand for infrastructure from the affluent persons that owned these vehicles, most cities were built with space in mind so their richest could enjoy their personal vehicles as optimally as they could. As time went on, and more people bought cars due to the ease of transport they provided, that infrastructure demand only increased.

Specifically in America, further pressure was given to state and local governments by automobile manufacturers to build better and better roads to more places so more people would have access to roads and therefore see value in owning a personal vehicle.

Then there's the interstate. Again, specifically talking about the states here, mostly... The Interstate systems were desired by the auto makers and people, but we're not strictly required. AFAIK the largest push for interstate freeways came from the military, so they could rapidly move equipment from one location to another. This is why interstates are so built up; if you compare the underlying structure of most roads with what's done for interstate freeways, the difference, at least, historically, is quite significant. The interstate was designed to have a batallion of tanks roll from place to place, something that would utterly destroy most roadways. Of course they can also move other equipment on it, since the majority of the remainder of what they would need to move is less damaging to the road than tanks.... Like planes. Many interstates are designed, on purpose, to act as impromptu runways to land or take off from. This enables the military to set up shop pretty much anywhere they need to, in order to defend the land.

The existence of the interstate only drove (no pun intended) more people to want and buy cars. Further compounding the problem.

Now, many years later, city streets are generally not built for you. They're not built with regular human lives in mind. They're built to act as conduits for emergencies so personnel or equipment can move from place to place with ease and relative speed. Public emergency services (police, ambulance, fire) are all geared around the existence of roads for transit. Because of this and a multitude of other, somewhat less notable reasons, roads continue to be a fixture in most cities and urban areas.

Another stupid (mostly American) reason is how far away everything is. The reason everything is so distant is a simple explanation: zoning. Commercial and residential zoning created problems where getting a plot of land re-zoned to build a strip mall or plaza is challenging at best. So since you live in a residential zone, all the commercial zoned services that you use, must be on different land in different areas. The nice thing about this is that residential zones tend to be much quieter than commercial most of the time, so homes can sit in quiet area while all the hustle and bustle of the city stays separate. This has somewhat changed on recent times but it still exists as a significant issue. Since zones of residential and commercial are generally not very small, unless you live at the edge of a residential zone that borders a commercial zone, essential services like grocery stores and shops are generally a significant distance away. Owning a vehicle and road infrastructure makes this a minor inconvenience at most, unfortunately it also makes this a major inconvenience for anyone who does not (thus driving sales of personal vehicles, again, compounding the problem). Again, in recent years, maybe the last 20-30, this has been changing, and we're starting to see, at least in large Metro areas, the rise of condos. Usually intermixed with commercial areas, it's a home you can buy that is surrounded by commercial services within walking distance (copy/paste for apartments).

Unfortunately, due to the military and historical reasons, as well as continued demand for roads from people living in residential zones that are further away, roads are and continue to be built, and maintained, in cities.

If you look "across the pond" to Europe, there are many examples of cities that existed long before zoning was even considered and where automobiles didn't exist that are very convenient to bike or walk through. Homes are intermixed with shops, and generally living in the city, while a bit more noisy than a residential zone, is otherwise very convenient for walking and cycling where you need to go. Mainly because cars were not a consideration at the time that those cities were constructed. Walking was common and cycling was not unusual, so the infrastructure reflects that.

We're seeing a resurgence of this kind of anti-vehicle infrastructure thinking among people, and with the rising costs of everyday living and the expense that vehicles can incur, both in operating them, storing them and maintaining them, it's easy to see why, especially when housing, in the form of apartments and condos, is getting closer to the commercial services that people want and use. However there seems to be a growing animosity among those that want more walkable and cycling friendly cities, with their car-driving counterparts.

I'm impartial. I own a car and live in a rural area, so I need one to get pretty much anywhere. My situation is not that of a city dweller and I see the merit in the walkable city. At the same time, I see the merit in drivable cities too. I wouldn't mind driving to a parking structure and taking a bus/subway/bike/whatever to get into any major city, since I do so very rarely. But I can't deny the convenience of driving into a city and parking less than a block away from my destination. Both arguments have merit and ultimately, I don't really have any "skin in the game" (so to speak), so what happens shouldn't be up to me, and cities should sort that out among their populous. I just know way too much about the issue, so I decided to comment. Sorry for the wall of text.