I guess my local electrical co-op is better than most. The only time my power goes out is from a hurricane or the rare snow/ice storm.
When I run my welder or turn down the ac I don't worry about the grid. When someone buys a farm and builds 19 new bigger than most houses they're not worried about the grid. So I find it funny that when evs are mentioned everyone becomes the grids parent and starts worrying.
Charging battery-powered vehicles is a very large load on everything from the meter on back to the power plant that the system is not currently designed for. It is not only a large amount of energy that is drawn in total, but it is a high amperage sustained load. Residential utility supplies are designed for intermittent, sporadic loading such as an A/C kicking on and drawing several hundred amps for a second, 30 amps for 10 minutes, and then being off for a half an hour. They are massively under-specified for continuous loading.
If you want an example, if you have an overhead service drop, look at how much smaller the wires going from the transformer overhead to the service drop compared to the much fatter wires they are spliced to just in front of the weatherhead. Common is 4/0 aluminum on your side spliced to 1 AWG aluminum on their side. The NEC requires you to size for an 80% continuous load, the utility sizes for closer to a 30-40% load.
Also look at the transformers. A large residential transformer is 25 kVA, typically used for houses with more than one 200 amp panel or in cities, this is often shared between several houses. This transformer can supply 104 amps at 240 volts on a sustained basis. (Note that these are connected to generally a couple of 200 amp panels in a house, not one 100 amp panel, and that a house with two 200 amp panels doesn't have a 100 kVA transformer to sustain 400 amps.) A more typical single-family residential transformer is 10 or 15 kVA with one per house, in a house with a single 100/150/200 amp panel. 10 kVA is 41.6 amps and 15 kVA is 62.5 amps continuously. Vehicle battery chargers vary, but a typical 240 volt "level 2" home charger will draw 30-40 amps and some Tesla home chargers can draw up to 80 amps, all of this continuously for hours until the car is charged. Somebody with one non-Tesla battery-powered vehicle in a larger house with a 25 kVA transformer would be fine as they probably don't draw more than about 15 kVA excepting the battery charger, even with the A/Cs running. Adding 9.6 kVA for a 40 amp charger won't kill that transformer. Adding two of them, maybe, after a while, if you aren't careful and don't charge both at once when the A/C, stove, etc. are on. Adding a sustained 9.6 kVA load for hours to whatever else the house is using already to a 10 kVA transformer will destroy it in fairly short order. Having three people living in a city on a shared 25 kVA transformer each charging a Tesla at the same time would draw 56 kVA plus whatever they A/C and dryers and such are drawing, and that transformer will die quickly.
Now realize the rest of the grid is designed similarly, it has enough capacity for some amount over previous peak usage, but not enough for a bunch of people to double or triple their previous amperage draws at their houses for hours at a time. Big continuous loads used to be the domain of commercial/industrial 3 phase customers, and all of these installations at least anywhere I've ever been had to have a utility engineer review the load and its timing, and ensure everything from the substation on out to the transformer(s) could handle the load. If you were going to draw a lot of power and they needed to upgrade lines, switching equipment, substation, etc. for your usage you generally had some skin in that game.
We can certainly upgrade he transmission lines, substations, distribution lines, and customer transformers to handle the load of charging battery-powered vehicles. It just costs money. Upgrading generation capacity, however, is a much thornier issue and money alone won't solve it.
