The big difference is that when a fault does occur on an automated train or an elevator or whatever, the thing just stops (usually). Then someone with a ladder and a toolbox comes along in due course to let everybody out or off. The problem with an airliner is that this option doesn't exist. If a fault occurs gravity will eventually win and the commercial repercussions are all too obvious.
Perhaps one day it will all happen but thankfully I doubt it will be in mine or my childrens lifetimes.