Coal is used to establish a lower bound.
Your analysis would result in the conclusion that charging an EV in France (90% carbon free electricity) causes the same amount of CO2 emissions as using one in South Africa (90% fossil fuel electricity).
The expansion of EVs has coincided with a massive drop in coal electricity share and a massive increase in solar PV and wind share, globally. Assuming that expanding EVs are being powered by coal is odd to say the least. Especially given that (at least where I live) 70%+ of EV charging is done at home, mostly using off-peak electricity, which tends to have a much higher renewable share.
Coal is rapidly been retired as a source of electricity generation - 85% of generation capacity being retired in 2022 will be coal[1] - and there hasn't been a new large coal plant built in the US for over a decade[2]. In Europe the amount of electricity being generated by coal is half of what it was at its peak.
Meanwhile, renewables now make up about a 87% share of new electricity generation capacity in the the US[3]. Europe is similar.
Pricing the CO2 emissions cost of an EV using the dirtiest and fastest declining electricity source (coal) does not seem fair or honest to me.
[1] https://www.eia.gov/todayinenergy/detail.php?id=50838
[2] https://www.scientificamerican.com/article/will-the-u-s-ever...
[3] https://www.renewableenergyworld.com/solar/renewables-are-87...