You do not have the infrastructure complexity and cost of trains. Because vehicles are small (pounds instead of tons), guideways are literally an order of magnitude cheaper. You can build track for $5 million per mile instead of $50 or $100 million per mile. You can build a grid system instead of arterial lines. Guideway is light so can be off the grid and easily avoid dangerous intersections with roads and other ground pathways. A single skytran guideway has capacity of 14,400 per hour - more capacity than 7 lanes of freeway or [3 tracks of at-grade light rail](https://www.liveabout.com/passenger-capacity-of-transit-2798...) and 50% more than grade-separated light rail (which is rare).

Your thinking is out of date.