When growing via sunlight, I don't trim. The sun's power reaches all leaves, and a large percentage of the sun's light passes through leaves to the ones that aren't getting direct sunlight.
When growing indoors, the lights aren't powerful enough to pass much through the leaves. Yes, the big fans collect, and store a lot of energy, but there's only so much it can store. If I have a huge fan that's blocking 15 or 20 smaller leaves below it, the majority of light goes to the large fan. But 15 to 20 smaller fans have a larger surface area, and can catch much more usable light.
I've heard both sides for as long as I've been growing, so I had to try a few grows using each method, and the results were overwhelmingly in favor of the trimmed plants. I mean, without question. But hey, try it for yourself and see what your results are.