Even on diesel trains they are far far far more energy efficient than cars. Current estimate is that it takes 3.7 liters of fuel to transport 1 tonne of cargo for 100km. That's incredibly more efficient than any car can get. Not to mention cars carry around on average 1.3 persons inside.

Train infrastructure is also significantly more scalable. You can add another train car for passengers at the price of one passenger car and you have increased capacity of that train immediately. Same goes to downsizing. Rails can be easily adapted to have overhead wires. Train wheels are metal as are tracks which means significantly cheaper maintenance and slower wear than asphalt and rubber.

It's nothing to do with ease of deployment. It's all about selfishness of people and their inability to or lack of willpower to change. Even if people switched to motorcycles, which are still ICEs it would still be a lot cleaner for the environment since it would effectively eliminate traffic jams and reduce road maintenance significantly. Not to mention not needing to move 1 tonne of metal for no more than 1 passenger.

It's very hard to do something if you only talk about it and not actual doing it. But that has nothing to do with technology itself