Walking can give you point to point, with more personal space than the frequent crush of a train or bus, but I don't think it's realistic to expect people to want to live in cities small enough that "always have a walkable commute" is a realistic goal.
Electric bikes/scooters/skateboards/etc seem like the best option in coastal California, but are a harder sell in places that get extreme weather. And have some issues compared to a car for the less able or more fragile.
Self-driving cars make congestion and usage probably worse, in my expectation, because you've eliminated one of the big downsides of cars, so I expect more demand for them compared to buses and trains.
Environmentally, the more realistic win - short of strict laws that basically just force people to not go with their first choice - honestly seems like just figuring out remote work. Reduce how often people have to travel across town at all. (That, and I'm not convinced that moving away for "perpetual growth forever" is such a bad thing.)
But instead this subject got 1 tiny paragraph near the end, in which this viewpoint "a form of degrowth".
"We can build more batteries, more cars, and more tunnels. And humans will be better off for it."
Honestly I just disagree with this take so much... I'm very far from a strident environmentalist but it should be obvious that this isn't the way forward.