Some specific crops grow better in the shade and the bonus is that they cool the air around them. That improves the efficiency of the solar panel. It's a win-win all around.

The one challenge is getting the mechanized equipment of industrial farming around the panels without damaging them. There are companies working on improving that too.

Some plants can indeed get saturated (they tend to tuck their leaves in past that point), but I could imagine more serious savings from the practice if the partial shading from solar installations reduces evaporation. In most places (particularly those where solar is most profitable) agriculture is limited by availability of water, so anything preventing evaporation is a potential boon.

Any increase in yield reduces the amount of land needed. I thought land use was the putative horror critics of solar were objecting to, so surely they'd want to cut down the much larger area used by farming?

A lot of plants outdoors are grown in partial shade via shade netting. In my head, it makes a lot of sense to supply some of that shade with solar panels. Likewise, it's a win because we "dual" use the same land surface area. We also probably save on water by not leaving so much of it to evaporate from the direct sunlight.

Maybe someone smarter or more knowledgeable can help out, but this strikes me as a very elegant solution.