Well, Musk also thinks that Tesla can't do it alone. :shrug:
That said, the vast majority of people with cars have exclusive parking spaces where it's easy to install chargers. (Way more than half.)
I've gone through the data on this.
In Japan, by law you have to have a parking space in order to register a car.
In other countries, there are two populations who don't:
1 - freeloaders who park their cars in street parking (originally intended for daytime visitors) overnight, while living in houses or apartments originally designed for car-free living. This happens almost entirely in big city neighborhoods developed before automobiles. Frankly this is a pretty small fraction of the population, well under 10%, and if these areas went back to being populated by people who live car-free, everyone would be better off.
2 - people whose spaces are in large shared lots or garages while their apartments are off to one side in high-rises. It's also very feasible to install chargers in these lots, it just requires a lot more landlord interest, so it'll happen late. But it'll happen as charging becomes a desired perk. This population is also smaller than most people think.
Together, these add up to less than a quarter of people who own cars. So I just don't think it's an issue.