California, a state of 40 million people, would disagree with you ;)
Not just referencing the blackouts we had last summer: CA also is heavily invested in solar power, and as a result, power is much cheaper during the day than at night (assuming you opt into time of use pricing). A battery for $2k would pay for itself in California quickly, because you can charge it when power is cheap during the day and run off battery when power is expensive at night.
Plenty of other US states have had blackouts as well; my parents in PA now own a generator due to repeated blackouts last year. If they could have bought a battery for $2k, they probably would have: generators are loud and dirty. And Texans certainly had a bad time with blackouts recently as well.