There was a proposed theory on this the spread of absorption created more stability in the power generation of plants over different conditions. This was supposed to be a more important factor than being able to absorb the peak and highest energy.
I think this paper is what I was looking for, thanks. I may have to reread it after becoming more familiar with the chemical/physical nature of:
> Photoexcitation energy is rapidly transferred through an antenna network before reaching the reaction center
I didn't know that. With this in mind, perhaps a better formulation of my question is not:
> Why are plants green?
But instead:
> Why are green photosynthetic pigments more common than others?
Based on my read of this paper, the answer to that would be that a pigment which absorbed only a single narrow band of light would be prone to being either over or under powered most of the time. Absorbing red and blue, but not green, provides more opportunities to deliver constant power at the reaction center despite varying light conditions.
https://www.science.org/doi/10.1126/science.aba6630