Trains should (and afaik already do) mostly drive themselves, but always with a conductor ready to make corrections or take over.

It’s not real driving if an AI is doing it.

When you have that many people, eliminating one/a few jobs doesn’t seem like it’d save much money/effort compared to the benefits of having staff present.

Plausible in metro systems in highly integrated areas, but the infrastructure cost would be monumental on long haul routes. Some automated safety systems integrated into the train itself (likely too resource prohibitive to network all the sensors and systems along the rails) can augment human drivers and make their job safer and easier though.

The Vancouver skytrain system has had automated trains running for decades and is one of the longest fully automated and driverless systems in the world.

Now, this is a metro and not proper rail/train, but similar enough.