Because it has to be repeated again and again: We need to drastically reduce the number of cars to solve our problems.
@AndiPopp than drastically invest in public transportation outside of cities…. The people there have no chance without cars…
@Grey08 Yes, this is a part of it. But increasing living density is also part of the equation. Many "non-city" areas are surprisingly unsustainable.
@AndiPopp there a minor problems first of all rental prices are insane in the city. Most people can’t effort that. Than not all people are capable to live in a city where it will be never dark or silent enough to sleep with a open window.The quality of life is also worse in a city and that will not change with les cars because there are not enough plants in a city. Also wind will be a problem between the “skyscraper” see NYC. There a many other social problems when you cram people in dens areas.

@Grey08 A few things to unpack. I give you the point of the rental prices, everything else I must kindly disagree.

The worse quality of life is not inherent to cities, but because people living in rural areas drive into cities: https://youtu.be/CTV-wwszGw8

People living in rural areas (who are financially and ecologically subsidized by city dwellers) create the problem they decry in the first place.

This does not mean everyone needs to live in Manhattan, but maybe at least Koblenz.

Cities Aren't Loud: Cars Are Loud

YouTube

@AndiPopp @Grey08 To add to Andi's points.

"Not enough plants in a city", how about we plant plants in 30% of the parking spaces? 40%?

Skyscrapers suck, and are a dead end, better to have medium rise and low rise blocks, better on every metric.

Noise: most noise comes from cars. You'd be very surprised how quiet cities are without the constant noise of cars driving around.

Light: This is a problem, but I bet that if we thought about it a bit longer, we can think of something.

@AndiPopp @Grey08 Also, to come back to the cars and noise point, even without the engine sound, cars are still quite noisy, just the sound from the tires hitting the pavement is very draining.