We've set up a country where it is too inconvenient and expensive for most people to use bikes or public transport.
Buses and trains outside the biggest cities are unreliable and even in big cities they are often expensive. Bristol, for example, has really congested roads but our bus system is terrible, no metro/underground, very few local train services.
Biking means taking your life into your hands as there are very few bike lanes, and those that exist often end abruptly with no way to get back onto the road safely and easily. I do still bike to work though, I just wear tons of reflective and hi-vis so no one has any excuse not to see me- doesn't stop cars pulling out right in front of me.
Walking isn't always easy either due to a lack of safe crossings, even around schools. Despite the new highway code supposedly making it easier to cross the road at junctions, at least half the cars we see each day seem to ignore the new rules.
Yet we build big sprawling new build estates with no space left for shops, doctor's surgeries or schools so that residents have to drive pretty much every time they leave their homes. Shopping centres and out of town entertainment areas are out of town- great if you want to drive out there as there's usually ample parking, but a nightmare for travelling there by public transport and you often have to drive between different shops as there are no pavements or crossings.
Children often can't get into local schools, so they often have to drive past walking distance schools to get to the school they are allocated.
I don't think we will ever get rid of all car journeys, but we do need to cut them down a lot.