Average home uses 30kWh per day. And that's average. Winter is higher, and would be much much higher if we were trying to use electricity to heat homes instead natural gas. Where do you live? CA? You have a lot more sun and land than other areas. Building the generation capacity in your area might not help areas that actually need the power to the north and east. And what if you need your car to have full power? What if you're not a low needs residential unit but a hospital? Or a factory? What if you have a couple low sun days in a row? What if your city just does not have enough power in reserves and its very cold or very hot?
Battery tech and solar is great, but its not the perfect solution.
to be fair, you need more than the EV. Using your EV battery as a power source to feed into your main house/home wiring is not crazy complicated, but it's not just a plugin.
I use 6kWh / day. (not sure how! but that's what the power company says)
A decent EV battery holds 20 kWh or more.
Boom. There is my night time storage buffer.