It's not that the understanding is atomized, we all fully grok the benefits of a move to non-car society. It's that individual action is often dangerous, irrelevant, or even counter-productive independent of a wider shift in consciousness and action, and currently reactionary forces are stronger than we are. Individually adopting a bike-first approach in many urban centers massively multiplies your chance of getting fucking murdered by people who despise cyclists who will clip you intentionally and laugh as you die.

I and several people I know have been chased off the shoulder and into ditches by aggressive drivers for daring to walk alongside the road. Like I don't think you grasp how sociopathic American drivers are.