Electrification of surface transportation is a huge win for people regardless of how the electricity is generated.
The problem is it presents a false dichotomy, or at least a choice which highlights merely a current state and not a move towards future improvements, and uses that blindless to make a case against EVs.
Thing is, even if a country is 100% coal and ICE right now (which is already not the case, China is not 100% coal), moving the fleet to EVs is still a good move. Putting aside an argument as to whether central power generation is 'cleaner' than distributed (ICE) generation, as long as a country also makes moves to renewables in it's centralized power generation, then the two things work in conjunction.
A lot of the current 'omg greenwashing' push-back is people confusing arguments for 'better' solutions with those for 'perfect' solutions. Which don't exist. Better is still worth doing, and paralysis until 'perfect' comes along is a big ol' waste of everyone's time.
Vehicles have limited under the hood space and are distributed.
But we definitely need to improve power plant emission standards as we move to electric.
(but no mention of solar, wind, drastically reducing our energy consumption, etc?)
Easy to look at : https://www.electricitymap.org
It's mostly plants and zooplankton
If by "max efficiency" you mean "less terrible than just wasting that energy" then sure but it's still a lot less efficient than a highway cruise.
Edit: why the downmod? Energy is energy.