Reconfiguring the built environment is not only achievable but has been done in the past. You can take a look at Amsterdam as an example. Look at pictures from the 70s or so and then look at it today.

You also don't have to "reconfigure" the environment. We could just stop building new highways and eliminate minimum parking spot requirements. We can change our zoning laws to allow for more medium-density. In Columbus, where I live we have a street called High Street that runs north/south and connects all of the walkable areas of the city and Ohio State University. It's relatively easy to just run a tram right down the road there and displace car traffic. There are low-hanging fruit. It's way cheaper than rebuilding highways which we do all the time, and if we can do that we can reconfigure whatever we want.

There are a lot of things we can do.

Starting from a point of defeatism is not something that's compatible with how I personally operate.