Yes, but by definition very few people live in low-population-density areas. Most people live in cities. That's what cities _are_ - the areas where most people live. We already are in the process of jamming most of humanity into super high density urban areas. Have you not noticed? The US came very noticably later to that process than did most of Europe, which urbanised a century earlier (I've seen it suggested that that's why the UK isn't very religious - the working class became 'de-churched' when they all moved to the cities during the industrial revolution), but it's finally happening in the US as well, as well as much of the rest of the world.
And food production uses less-and-less human labour, which is why there are so few jobs in the countryside.
I think that's an overstatement. Very few places look like Manhattan, HK or London.
Even in high density areas around cities there is still considerable sprawl. Have you ever been to New Jersey? It's the most densely populated state in the US, and even then it's mostly suburban and utterly dependent on cars.
Yes, there are good mass transit options* (for the US) to get into Manhattan, but not necessarily to other parts of the state.
Even in Europe, a very common configuration is dense cities, but also medium density villages surrounded by countryside connected by roadways.
Yeah you can get around London by tube pretty well, but even out in nearby Kent you need a car to get around. Certainly lorries do need roadways. Plumbers and other workmen aren't getting around by bicycles and buses.
Same in Germany. Frankfurt is pedestrian friendly, but getting out to Bavaria needs a car, or a lot of money and patience by train, and options get very limited after that. Certainly many taxis running around.
A study coming out and saying "yeah, well, these roadways were a terrible idea after all" just isn't very useful information or very cognizant of how people live.
I'll agree more could and should be done in city centers above a certain density.
I also think the ride sharing, EVs and other novel forms of transportation can also help. There are real opportunities with rentable e-scooters, provided car traffic was limited in dense areas so aholes don't mow people down.
However, cars are by far the most flexible, enjoyable and time efficient way to get around the world, and that's why they are ubiquitous. Changing that fundamental conclusion isn't going to happen until flying pods or teleporters are invented, eg, not anytime soon.