Don't forget maintenance! Nobody sane would disagree with you on the regional dependence issue. Nearly every major energy category, from coal, solar, wind, oil, nuclear, hydro...all are regionally variable. Busses, trains, cars all regional.I don’t know. There are presently good use scenarios for PHEV’s. Even “fuel” cost. With present supercharger rates it’s arguably cheaper to road trip in a Prius. For most people the advantage still lies with EV over PHEV because we can charge at home. But for those who road trip a lot, depending where they travel (gas price and supercharger price variables) it can certainly be cheaper to travel in a gasser. It will be interesting to see if supercharger rates continue to climb. We are seeing 80 cents per kWh in some places now. (At least for the non tesla EV drivers). I suspect it will be very region dependant.
No matter what trajectory we are on as a planet those variances will continue.
Unquestionably there are places where ICE, PHEV and EV will each have strong local preferences. That is regardless of eventual dominance of the most efficacious solutions.