>> But what’s the point? Why do individuals need level 5 cars?
Because there are places that public transit will never cover? I've been places in the American West that are 50+ miles from the nearest paved road, stop sign, or restroom. I don't think they're getting bus or train service any time soon.
No, but you could have public-rideshare in some of these places.
Level 4+ cars may be quite expensive for some time. Operating costs of L4+ vehicles will likely be low compared to human-driven vehicles (counting the cost of the driver). So, it could lead to car sharing in situations where we don't accept it currently.
> that are 50+ miles from the nearest paved road, stop sign, or restroom.
US population density is lower than most of the developed world, but what you describe is a tiny share of miles driven and can be effectively ignored for now.
Why not just make tons of public transit at that point using the level 5 tech instead and cut traffic?