This is a FEMA map which means government agencies planning for events are the primary audience.
The drought metric is about risk to agriculture, not your family garden :)
Yes, there's a lot of nuance hiding in the aggregate, which is why I think it's generally more useful to look at the Census Tract View. It's also helpful to look at individual risks, which you can do by selecting the red menu at top left. Wildfire Risk is an important one for those to pay attention to in the west.
Indeed there are no perfect places, but risk isn't the same everywhere. I live in an urban area of Boise that is very low risk yet we're surrounded by high risk (mostly wildfire). Which makes sense, wildfire risk is low in more urban areas (though not zero), but the risk of range fires is very high in the foothills. A house on a hill has great views which seems desirable until you realize the hill is covered with brush and fire races uphill very quickly. This isn't unique to Boise, look at other urban centers in places like SLC, Denver, Spokane, Phoenix, etc. and you'll find islands of blue in the sea of red and yellow. Yet Americans love living in the forest and/or having views, so we keep building in the WUI and other high risk areas.