We had a mass attack on a train recently, the driver radioed ahead and got his train shifted onto a different line so he could stop the train at the nearest station (which had a police station across the road).
That's the kind of thing that is hard to automate because while you can automate any routine operation (eventually) it's the none routine things that get you.
Planes and Trains have both had increasing levels of automation for decades and that's fantastic, humans are flawed/get tired/get distracted but you still need a human in the loop who can decide what to do when the unknown/unexpected happens and for that human to be effective they need to be able to operate large parts of the vehicle without the automation and understand the basic principles of the system as a whole well enough to decide what they should do that won't make the situation worse.
In planes that's the Pilot in Command, in Trains it's the driver.
That's the kind of thing that is hard to automate because while you can automate any routine operation (eventually) it's the none routine things that get you.
Planes and Trains have both had increasing levels of automation for decades and that's fantastic, humans are flawed/get tired/get distracted but you still need a human in the loop who can decide what to do when the unknown/unexpected happens and for that human to be effective they need to be able to operate large parts of the vehicle without the automation and understand the basic principles of the system as a whole well enough to decide what they should do that won't make the situation worse.
In planes that's the Pilot in Command, in Trains it's the driver.