They need to charge from the road while moving. Companies are working on this. Then not such a big battery is required which makes it much more affordable.
Did you ever think about how expensive that would be to implement and maintain on a country-wide basis? And you would still need to greatly enhance the generation capacity that would feed the roads. A reduced capacity in-car battery would only be practical after the road rebuilding program was well underway.
How long are today's roads left to deteriorate before they get a quick skim and resurface only to be dug up within a year or two to get to the rotting pipes below the road?
Doesn't mean they'll succeed.