> This country has always been highly spread out and it’s simply not practical to adapt the entire countries infrastructure to change that within a lifetime.

Considering the country went from (mass manufactured) cars not existing to the majority of people owning a car, public transit system being demolished, urban freeways and interstate highways all within a lifetime; why is it suddenly impossible to do the reverse?

The USA was built on the back of rail. "population density" and "geography" are fundamentally a-historic excuses. Not only can it be built, it's literally already been done before. In a time when population density was significantly lower and geography significantly more challenging.