>I wonder if the residential 230v standard in many parts of the world contributes to EV adoption.

The veracity to which the government enforces rules that make work for variorus electrical professionals and manufactures has a lot more to do with it IMO.

In some places an EV charger install is a "here's the best we could do, you might trip the main breaker if you fast charge while running the stove and water heater and dryer all at once"

In some places it's permits and panel upgrades, and, "have to bring X up to code while we're at it, that'll be <1/3 cost of car>", and, and, and, (to the cheers of the same demographics who complain adoption is to slow no less).