This argument is dead wrong and impeding progress. As other commenters have mentioned, stationary sources are much easier to filter. They're also more efficient than thousands of small internal combustion engines. They also produce pollution away from where people are breathing it.
Electrification of surface transportation is a huge win for people regardless of how the electricity is generated.
The argument for public transportation is not dead wrong nor impeding progress. Expanding bus systems is something communities can do today in order to reduce their carbon footprint and their traffic levels.
The argument tarboreous put forward, as the parent, is presumably the one under discussion.
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.
Electrification of surface transportation is a huge win for people regardless of how the electricity is generated.