More photons :-)
Lights have two purposes, to see, and be seen. To do the first, bright lights, aimed to illuminate where you need it, without too much scatter. For the speeds and paths I commute, that's anywhere from 4-10 feet in front of me. To do the second, scatter is ok, but not great. It'll make you more visible, but you may not be as visible from far away.
My setup is like yours - strobing headlight parallel to the ground, steady headlight pointed at the ground so that the main spot is ~6ft in front of the wheel, and the spill runs 2-3ft ahead and behind the spot. Back is a slow strobing taillight.
PS - In before "
yellow is definitely better". Subjectively, people prefer yellow, and it
should cause less glare, but objectively there is no strong evidence.