If the plant doesn't use all the extra chlorophyll as the article suggests, then what purpose does it serve when competing against other plants. From what I gleaned from the article, this in my mind is akin to a track athlete having 50 pairs of shoes outperforming an athlete that only has 1. If the athlete can't use all 50 pairs of shoes at once, then what benefit do they offer?

Can you clarify your interpretation of that statement because I don't get it.

It absorbs light which prevents other plants fro being able to access it lower in the canopy. The absorbed light doesn't get converted to food, but is absorbed as heat energy which is radiated away.

To use your analogy, there is a set number of pairs of shoes available. Two athletes are to compete against one another. If one athlete wears one pair and takes all the others and throws them away, the other athlete has to run without shoes and will probably lose.

I didn't exactly get it either, because if they didn't absorb the photons with the extra chlorophyll, it's not like it would go to the other plants anyway...

I just assumed there is a more complicated reason involving competition that the article didn't bother going into.

So it didn't really answer the question...

It hinted at an entire class of explanations.

Plants that may be "behind" this plant in the path of direct sunlight are starved of sunlight by the increased absorption. Thereby reducing their ability to compete for other resources.