First, it allowed the building of suburbs, which just wasn't feasible before. This in turn led people to push zoning laws such that building anything other than a SFH became illegal.
Second, it contributed to the dismantling of street cars and other forms of public transportation.
Third, all these cars new housing developments needed roads and this typically led to the destruction of poorer and usually more ethnic neighbours.
Fourth, driving everywhere is like living in an insulated bubble. You don't have to deal with your fellow man. Things like Skid Row (LA) or the Tenderloin (SF) don't touch you because you can just drive around them in an airconditioned bubble. I honestly think this contributed to making people care less about the plight of their fellow man.
Fifth, voters routinely complain about the cost and taxes of public transportation but think nothing of all the subsidies governments provide for driving (eg building roads, having gas stations, building so much parking, having cheap or free street parking even in densely populated cities with good public transportation like NYC). Yes there are fuel taxes. No they don't pay all these costs.
Lastly, we seem to be comoletely comfortable with the cost in death and crime of car ownership because of the personal convenience. Tens of thousands die in motor vehicle accidents every year. There are crimes like being a serial killer or kidnapping that almost require having a car. Do we really wonder why such things exploded post-WWII?
The affordable housing crisis is depressing because it's another stark reminder of just how little a fuck people give to people who aren't in their tribe. The many barriers erected are simply aimed at making poor people go away. That's it.
And the problems are at every level of government.