Make no mistake, bikes are much, much, better for urban centers than cars. But the overall problem isn't cars, it's individual traffic in densely populated areas.
Certain policy here in Europe simply assumes that people stay in their surroundings ("15 minute city") and rarely, if ever, visit parts that are farther away individually.
Public transportation, however, is naturally biased. It can be much quicker to get 10km north-south than 5km east-west, or the other way around, depending on the city. And, of course, public transportation is often lacking quality compared to individual traffic. (Taking a bike across a bicycle road vs. getting into a crammed subway train in July, for instance.)