Yes, busing people around in multiple occupancy vehicles does in fact reduce capital costs. That's why public transit networks in Eastern bloc countries were so

Yes, busing people around in multiple occupancy vehicles does in fact reduce capital costs. That's why public transit networks in Eastern bloc countries were so extensive, often reaching every little town and village: communist economies couldn't afford to produce enough personal vehicles, so they ran buses instead. But, reduced capital costs is evidently not what people in developed economies are actually necessarily after. Turns out, people are perfectly happy to spend extra resources to acquire exclusivity rights to a vehicle, because of flexibility it affords them. Having a private transport allows you to go where you want, when you want, and in almost all circumstances do it much faster than via a bus. The opportunity cost of time spent walking to bus station, waiting for a bus, and then taking longer to travel is for many people very significant, thus they pay for private transportation to recover some of that time.