The problem would vanish if we moved from city living to small town living. We only have city living because everyone needs to get to their office which created high density housing near the city centre and urban sprawl everywhere else; both of those things would not be a problem if we moved away from city living and focussed on smaller towns instead; that way we could still have services centralised to a local community that works for everyone rather than having millions of people in one place which cause extreme mental distress for many people (see the mental health crisis).

I commute through the city, if one person crashes their car it impacts thousands of people getting home on time to see their kids before bedtime, how is that a nice way to live?

That's exactly my point point. Nobody should be driving their car through a city.

As for mental health issues, some people like cities, some don't. Without the traffic it would probably be a lot more pleasant.

It's tough to have a successful small town without it growing into a city.

Agree - I've been thinking about what the city would be like if all cars (except taxis) were banned during rush hour. I'm struggling to see how it would lead to anything but a better public transport network and a better standard of living for most people that need to commute during busy hours.