I know what you’re addressing, but vehicle batteries aren’t going to go to zero because they are charged up once per day.
If you’re going by the 80/20 rule, you can extend those batteries out considerably longer than the normal life expectancy also.
Vehicle manufacturers are guaranteeing the life of the batteries out 8-10 years, and commuters aren’t complaining about batteries dying off.
People work about 220 days per year. I’ve forgotten the exact amount.
We’re not talking about the power company taking the full charge either.
As for people needing all their charge, they will know how much they need. They can sell the extra.
But they are complaining. The guarantees for 8-10 years have a caveat, that they guarantee perhaps 70 percent range as compared to when delivered new. Customers don't like that aspect. The more cycles of charging/depletion greatly decrease percentage of charge retention, and manufacturers won't guarantee percentage beyond 70 percent or so. Also, manufacturers may decline to honor warranties if the batteries are used to feed the grid.