The big problem with sprawl is that it's subsidized. The federal government taxes the population at large and uses that tax money to build large roads and lay down the necessary utilities, sewage, and drainage. Interstates and interstate connections (viaducts, onramps, offramps, etc) come purely out of the FHWA budget which comes from taxes. Gas taxes help but the federal gas tax hasn't been changed since 1990 (indexed for inflation that's basically been a discounting gas tax) and as fuel efficiency standards increase and hybrid/EV penetration increases gas taxes end up netting less money per mile driven. Add to that the fact that cars are getting heavier in the US, increasing wear-and-tear on existing roads, and you're basically making maintenance of roads in the US cost more money per taxpayer. Some states have been increasing vehicle registration fees to compensate but that remains very unpopular.

Local roads are initially funded by the government and based on whether they are collector roads or arterials, state and federal governments allocate extra money to these roads. But when construction finishes these roads often need to be maintained by local municipalities which is when the problems come in. Often times municipalities, especially ones with lower incomes, begin having trouble maintaining roads. Higher income municipalities raise local taxes to pay for their roads but Americans also hate paying local taxes which makes this unpopular and often unviable in poorer municipalities where incomes cannot accommodate the extra tax. That's how you get huge, sprawly cities that have terrible pavement. My city is struggling with this. The rust belt has tons of cities with this.

Moreover as the US population increases we continue to sprawl outward, destroying nature with sprawly housing developments that are viable because federal and state governments often pay for initial development. You mention democracy but there's not that much democracy going on. Often times rural voters aren't organized enough to create the kind of opposition to sprawl that urban voters have. You can't have opposition via public comment in a rural area because there is no planning agency which listens to public comment in many rural areas. In fact that's often why developers target unincorporated rural areas in the first place.

Unlike Europe, Asian countries are fine with car use, but don't subsidize it nearly as much as the US does. Japan, outside of Tokyo (which is a huge city and an outlier in the way NYC is), has narrower and fewer lanes on their roads for given traffic volumes. Public street parking mostly doesn't exist and authorities quickly tow vehicles that park where they're not supposed to. As such there's a robust market for parking lots. The closer you are to a city center the more vertical, compact, and expensive the lots are. The further you are the cheaper the lots are. In really rural towns the towns run parking lots that are basically free during the day.

The US does a lot to encourage car use. It has much higher LOS standards for its roads than other developed countries, it uses federal and state tax money to offer free parking, police officers are kind to drivers and let them overstay parking limits for longer than they should and only ticket the most flagrant offenders tacitly allowing everything from using your phone in the car to styling your hair in it. And this car culture is irrational and taking up an increasing amount of GDP and emissions.

Also if it's democracy that's your problem, this article in Colorado is all about democracy. The voters voted in a pro-transit governor, they voted in the tax increases to fund additional transit, and they approve of planning officials who refuse to widen highways. So car culture isn't as popular in the US as some think. There is an increasingly vocal minority of people who aren't happy that car culture is losing its popularity though.

This has never stopped politicians before, not really sure why it will now.

Polis is much more than a pro transit governor. He's a successful serial entrepreneur, he's gay, he's charming in a nerdy way, and he's pragmatic. I dont think his election proves much about political will in regards to transit policy.