Automation with short trains is similar price to long trains, but the short trains will run a lot more often and that will attract riders who have a choice of driving or not. If they miss their bus/train or have a long wait for their bus/train they will fix that by driving. However if they try transit and service is frequent they will realize that transit works just fine and so they will choose to not drive even though they can.

Frequency is freedom.

Nothing feels slower than standing still. Sitting in congested traffic sucks, and so does loitering on a train platform or a bus stop.

When the vehicle arrives so quickly you don't even consider the timetable or care if you just miss a train transit is an easy choice.