I'm trying not to be smug, but are you under the assumption that the delivery of physical forms of energy is simple? Distributing, on average, ~1.5B liters of gasoline, with different qualities/chemistries/regions/etc, every day in the US has immense amounts of complexity. Now do that for coal, natural gas, heating oil, etc.

Managing time of day for charging isn't a more complicated problem than any of those.