We have these 'electricity trains' already in a sense, but they are tractor trailers containing fuel oil. It's not as crazy as it sounds, but there are better solutions available.
Usually, the issue with this kind of thing is that
* this is a form of energy transmission that requires labor for the actual transport (the train crew) and so is automatically much more expensive and difficult than a dumb pipeline or power line which requires much less staffing
* it's hard to create energy storage that isn't also a bomb in the wrong conditions, and train tracks pass through populated areas. Fuel already has restrictions on where it can be routed because there have been fuel train explosions.
* this is a form of energy transmission that requires labor for the actual transport (the train crew) and so is automatically much more expensive and difficult than a dumb pipeline or power line which requires much less staffing
* it's hard to create energy storage that isn't also a bomb in the wrong conditions, and train tracks pass through populated areas. Fuel already has restrictions on where it can be routed because there have been fuel train explosions.