I even read that purple bacteria appear to be older than chlorophyll photosynthesis. So either absorbing green, the peak of the solar spectrum is TOO much energy (heat can disable the enzymes) or that part of the spectrum was already filled by organisms so the green ones took what was left.

Chlorophyll is also composed of many subunits that likely have been added as enhancing features over time, like energy transmitting antennae structures that funnel the photon energy to the reaction center.

I used to date a woman who was researching the dna structure of photosynthetic bacteria. :D