Huge bulk storage capacity that is mobile too.
For extremely small values of 'huge'. 100kWh can power a dozen houses for a day or two if they're a bit frugal, way less if cooking, showering and/or heating is electric.
I suspect EVs will not only be storing charge for the grid shortly but will be moving it too.
For data there may be a lot of bandwidth in a stationwagon, for energy less so (unless as hydrocarbons).