I have been wondering why elevators aren't just vertical trains. No limit to distance, and several cars could use same tracks. Currently elevator shafts can res

I have been wondering why elevators aren't just vertical trains. No limit to distance, and several cars could use same tracks. Currently elevator shafts can reserve huge part of floor space. Down going cars could run motors in regenerative mode. So there's no need for heavy counterweights or heavy ropes. Another effeciency trick is trying to get people going to same destination into same car, reducing number of required stops. Might add some latency, but makes overall throughput better.