Why do you assume that public transit produces substantially less particulate emissions than EVs? I'm sure you've smelled ICE busses before, but even if you upgrade those to electric, Electric busses are very heavy, leading to an outsized impact on road/tire/break wear: https://pubmed.ncbi.nlm.nih.gov/35780985/

Subways have wear-related particulate emissions too, with the added disadvantage of them being less easy to vent: https://nyulangone.org/news/pre-covid-19-subway-air-polluted...