We've certainly come a long way in cleaning up engine exhaust, but the job isn't finished. As you point out, this is about direct health impacts, not CO2 and global warming.

If you want a breath of old air, come by my neighborhood and follow some of the lifted big pickup trucks that have been aggressively straight-piped with bigger turbos (you can hear them spooling), the better to emit "Prius Repellant". Oh yes, and at my (first) retirement party, I was given a can of LA Air, from the 1960s, well-labeled as such; just like Chris is holding here:


And, CNG buses now have particulate traps, too. Turns out that, while CNG produces much less particulate as diesel, what they do produce tends to be in the ultrafine category that's not particularly good to breath either. Different issues, but similar equipment to deal with it.

Eventually, EVs become what they've always been: the most practical thing in urban areas where you really don't want ANY exhaust emissions. The fact that they can also be better for greenhouse gas emissions (depending on what's used to generate the electricity) is a bonus.