Electric traction motors are far more efficient than ICEs. That's why diesel locomotives don't actually connect the diesel engine to the wheels. The diesel engine generates electricity, which turns electric traction motors.
Same with the really big earthmoving equipment - those gigantic dump trucks down at the strip mine are using electric traction motors powered by diesel generators.
Why don't we do this in cars? Space and complexity.
So what's the point of all electric cars? It separates the energy generation from the energy consumption, allowing flexibility in the energy generation. That coal plant you decry is a lot more efficient than an ICE. And other electricity generation sources have other benefits. The problem has been getting the power from the power plant to the car so that you can use electric traction motors.