It definitely is more eye catching in traffic
You've heard of target fixation, right?
I can see the desire for brighter illumination to see where you're going, but that's not the only consideration here. In addition to a small safety issue (consider drivers with astigmatism, or older drivers, or drunks) where you might be negatively affecting oncoming traffic's vision, there's also the courtesy factor. If I'm driving or riding, I find a bright light in my mirrors annoying and distracting.
Last and leastly, consider light pollution and / or that you may be shining your headlight through windows, while driving along curvy roads or parking at homes and businesses.
Brighter isn't always better. And neither is louder, while I'm on my soap box.