When people feel there’s more room for cars/infrastructure is more hostile to walking, they are more inclined to buy and use a car. That’s why adding lanes to highways never works to reduce traffic. You are not making more space for the same amount of cars, you’re inducing non-car owners to switch and get one, or already existing car owners to use it more, resulting in more cars in circulation.

Similarly, autonomous cars are perceived as taxis which people irrationally perceive as emotional license to acquire and use a car. Narratives like cars as freedom or tech companies coming to take your car.

Sure, it is counter intuitive, but there’s a billion dollar marketing industry dedicated to exploiting this and other similar cognitive biases. See green washing and the use of recycling to promote further consumerism. Or using health labeling to keep unhealthy foods in high demand, etc.