This math is bad and shouldn't be used as a justification. It presumes that every charger is always available, that variable battery conditions and traffic conditions make reaching that charger every time, and that drivers have time to drive to the fast charger and spend 30 minutes there every time their car has low battery.

I drive a new EV in the Boston metro, I do not need to drive most days. Charging without an in-home charger is a massive pain even with Superchargers within 20 minutes drive and a 300 mile range.

A trip to the super charger takes about 1.5 hours assuming its available when I arrive, I can only make the trip when the car needs charging or I am wasting time and energy. The exact time I will need to make this 1.5 hour trip work is variable. It depends on battery conditions, traffic conditions, and what I need to do. I cannot assume that the car will be charged when I need it to be - if I need to depart on Friday evening, or unexpectedly needed to get groceries during the week - I am obliged to spend the 1.5 hours at that moment.

To avoid these problems, I generally need to charge the car when it has ~30-40% and for battery protection I can only charge to 80%. Turning a car rated for 310 miles range into one with ~100-120 miles of usable range and a 1.5 hour weekly maintenance schedule. That range could be further reduced to 50-70 miles in winter conditions. The stalls at charging station charge by the minute, so you can't exactly wonder off.

With a reliable home charger, these problems mostly go away, even a slow 5kw charger should charge the car overnight - and a typical tesla installation delivers 11kw. A renter with no ability to plugin and charge overnight will have a tough time with an EV compared to a gas car.

I live in the SF Bay Area and the local shopping centers closest to me have zero EV chargers. California is supposedly going to mandate that all new vehicles be electric in 2035 but that's obviously a ridiculous fantasy; the deadline will be pushed back or eliminated.

How many is enough is a complicated thing though. You don't need there to be as many pumps as cars because there is enough everywhere that you know with certainty that you can find one any given time within 15 minutes and be refueled in 5.

If you have a charger or as many chargers at your apartment for the number of electric cars you know you are going to be able to charge with certainty.

If you have some small number of chargers at work do you know that you are going to be able to charge? Are you going to go into work park at the charging spot for 30 minutes then play musical chairs with your coworkers instead of working or are you going to park for 9 hours then leave at approx the same time as others ensuring that exactly 5 cars get charged per week despite being able to theoretically charge 336 per week in 3O minute blocks.

Regarding trips to the grocery store. Did you spend 30 minutes in a parking lot of a grocery store or mall this week? I haven't this month and even so you can't be sure that one of a small number of spots are actually available.

Currently plug in vehicles are what 1.9% of cars on the road. A relatively small number of spots scattered here and there is enough for this to work better than expected but trying to scale this begins to get pretty stupid pretty fast.

What does this look like with 1 in 3 cars? At 2 in 3 cars? How does it look like when you try to put enough chargers in the place where people incidentally land for extended periods of time instead of just putting them in lots of homes and apartments?