Couple of things here, you're discounting completely the effect of distributing the passenger load across a network, secondly there's no reason why small minicars can't run on the network on high-traffic routes in addition to the smaller ones.
The important points are:
Point-to-point unlike trains (hub-hub) and busses (every stop).
As a result, load is distributed across the network.
Small offline stops like busses.
Complements other systems (tube, freight trains etc.) - if you can separate freight from passenger rail that's a massive win (eg. capacity, schedules).
In-car switching lowers headway, does not require centralised coordination.
Cars do not need to park - recycled on the network.
Sleeper cars.
Cars can go direct from warehouse to local shop, as the small cars can berth inside the warehouse/shop for loading/unloading.
Power supplied in-track, possibly with backup batteries, but not neccessary depending on implementation.
Separate track from pedestrians etc.
Prefabbed track for quick build-out and maintenance. Rail and road require preparing the surface rather than driving poles into the ground.
Separated steering, load, drive systems, unlike rail which has to compromise with a single conical wheelset.
No derailment.
Tighter turning than busses and trains, so you can fit it where they cannot go, note we don't always need to run at high speeds in cities, only intercity.
Suspended systems can easily tilt - better ride comfort and tighter turning at high speed.
Weatherproof, more so than bus or rail.
More tolerant of natural disasters if above grade (flooding, earthquakes etc).
Better land use if pole-mounted, lighter cars (say 20 people max) than light rail allows lighter-weight structures, and hence lower wear and noise. Heavy vehicles wear roads and rail much faster.
Dumb cheap rails, only power, no switching or coordination. This is a big cost for trains which need to rely on slots and schedules.
Coordination is done via protocols to allow for decentralised on-demand use.
3D track allows say transport to halfway up a building.
If you have dual-size compatibility (big and small) this allows individual parcel delivery, recycling collection, use in factories etc. with the small system.
Conventional trains cannot do any of these things (tilt is not as good). Yes they are THE most efficient at transporting large numbers of people / freight from eg. the Superbowl, but history has shown they are far from a complete solution.
The features I'm talking about here are not gadgetbahn ideas, they are real advantages for what is a new system, not a car, a bus or a train. This can complement existing systems. Cost is a misnomer when you factor in switching and coordination for busses and rail. Last mile becomes much less of a problem.
Pitching a more personalised transport is easier. If you standardise the track and protocols you can have many companies building it. You can run fibre, power, solar panels (if suspended) in the same track for infra buildout in 3rd world countries.
For comparison, the numbers for an example system:
At full occupancy (which seems to be what everyone quotes for rail, discounting economies of running routes off-peak etc.) 20 people with 10sec headway = 7200 people /hour on one rail. If we say we can fit 2 rails per train rail width-wise and another 2 heightwise, that's 28800 people down the same railtrack profile, which is comparable.
This is also leaving out platooning eg. Virtually coupling 2 cars together, so slightly longer platform which doubles your throughput to 57600. This is different to a train as platooning is a temporary arrangement.
Given a 2min loading time, you would need say 12 platforms to support this from a single station, but that's normally aggregated from multiple stations funneling into the same track, so you'd only require that at terminuses for instance.
The important points are:
Point-to-point unlike trains (hub-hub) and busses (every stop). As a result, load is distributed across the network. Small offline stops like busses. Complements other systems (tube, freight trains etc.) - if you can separate freight from passenger rail that's a massive win (eg. capacity, schedules). In-car switching lowers headway, does not require centralised coordination. Cars do not need to park - recycled on the network. Sleeper cars. Cars can go direct from warehouse to local shop, as the small cars can berth inside the warehouse/shop for loading/unloading. Power supplied in-track, possibly with backup batteries, but not neccessary depending on implementation. Separate track from pedestrians etc. Prefabbed track for quick build-out and maintenance. Rail and road require preparing the surface rather than driving poles into the ground. Separated steering, load, drive systems, unlike rail which has to compromise with a single conical wheelset. No derailment. Tighter turning than busses and trains, so you can fit it where they cannot go, note we don't always need to run at high speeds in cities, only intercity. Suspended systems can easily tilt - better ride comfort and tighter turning at high speed. Weatherproof, more so than bus or rail. More tolerant of natural disasters if above grade (flooding, earthquakes etc). Better land use if pole-mounted, lighter cars (say 20 people max) than light rail allows lighter-weight structures, and hence lower wear and noise. Heavy vehicles wear roads and rail much faster.
Dumb cheap rails, only power, no switching or coordination. This is a big cost for trains which need to rely on slots and schedules. Coordination is done via protocols to allow for decentralised on-demand use. 3D track allows say transport to halfway up a building. If you have dual-size compatibility (big and small) this allows individual parcel delivery, recycling collection, use in factories etc. with the small system.
Conventional trains cannot do any of these things (tilt is not as good). Yes they are THE most efficient at transporting large numbers of people / freight from eg. the Superbowl, but history has shown they are far from a complete solution.
The features I'm talking about here are not gadgetbahn ideas, they are real advantages for what is a new system, not a car, a bus or a train. This can complement existing systems. Cost is a misnomer when you factor in switching and coordination for busses and rail. Last mile becomes much less of a problem. Pitching a more personalised transport is easier. If you standardise the track and protocols you can have many companies building it. You can run fibre, power, solar panels (if suspended) in the same track for infra buildout in 3rd world countries.
For comparison, the numbers for an example system: At full occupancy (which seems to be what everyone quotes for rail, discounting economies of running routes off-peak etc.) 20 people with 10sec headway = 7200 people /hour on one rail. If we say we can fit 2 rails per train rail width-wise and another 2 heightwise, that's 28800 people down the same railtrack profile, which is comparable.
This is also leaving out platooning eg. Virtually coupling 2 cars together, so slightly longer platform which doubles your throughput to 57600. This is different to a train as platooning is a temporary arrangement.
Given a 2min loading time, you would need say 12 platforms to support this from a single station, but that's normally aggregated from multiple stations funneling into the same track, so you'd only require that at terminuses for instance.