> Cars are by far the least space-efficient method of transporting people
Not true in practice even if true in theory; in many places the average full-size bus contains fewer people than would fit in a minivan.
The problem is you need 5-10 years of reliable public transit in an area before non-transit users begin to convert (or transit users begin to move in).
Suburbs (with local amenities) with light rail connectivity into urban centres might actually be awesome.
I really wish someone would be a modern city from scratch.
If you myopically look at the instantaneous usage of infrastructure then you could argue that most roads are pointless because they are, on average, empty.
The bus might have less than 5 people on it at any given moment you observe, but over its >2 hour route it transports dozens or hundreds of people between stops.