China has traditionally had the opposite problem: cars had decent enough emission equipment while coal plants would frequently disable their own (coal contributed to more of Beijing’s problem than vehicle emissions, mainly because of poorly operated heating plants). With the crack down on pollution, that is changing, though the real clean up happens when they move off coal (to NG, renewables, and nuclear).
Decoupling transport traction from point-of-use fuel source, and centralising what emissions do remain, are both net gains. There is some net total efficiency improvement in going from fuel-based to electric traction, even with coal-fired generation.
All told, the process moves toward fossil-free energy by multiple mechanisms.
