The small bike light I used before I bought flashlight has two small lenses on the side, so the visibility from the side is very good. My new flashlight, I believe like all or most others mentioned here, doesn't have this feature, which I noticed on first use. That's because they were not designed for bike use. So they are not perfect. Room for improvement and opportunity for innovations

Only speaking for myself, but the flashlights I use, can be seen from all angles, even the rear!!

How does it do this? Again, only speaking for myself again, the flashlights I use put out such a large footprint, it can be seen at all angles. I have had cars come up from behind, and want to know what this was..
See for yourself..
What I call the "footprint" is the light shining on the ground. On my lights, they can see that big time from the rear and from the side. From the front, coming toward me, it is like a trip to the sun!!