The math literally works.

The US mandates by law that we grow a fuck ton of corn to mix 10% ethanol into gasoline.

If you replaced just those cornfields with solar/wind, they would power the entire USA and a 100% electric vehicle fleet. That includes the fact that they are in the corn belt with less than ideal sun conditions.

We aren’t even talking about any farmland that produces actual food or necessary goods, just ethanol as a farm subsidy program.

The US is already horrendously bad at land use. There’s plenty of land. There’s plenty of ability to build more grid capacity.