I’m probably not willing to carry such a thing, unless you can get it to weigh less than 4 ounces (short answer: you can’t.)
I hike almost exclusively on-trail in the eastern US; these are not vast wilderness areas, and the trails (while not crowded) are well-hiked. I tend not to do reckless things. In nearly 40 years of such backpacking trips, alone and in groups, I’ve never once been in any situation that would come anywhere close to any rational definition of “emergency.” So, my risk of getting into the kinds of no-help-likely situations you envision are quite low, perhaps to the vanishing point.
For me, you’re trying to fill a need that doesn’t exist. Therefore, the chances that I’d need such a thing simply aren’t worth the cost (in weight) of lugging it around.
Drones could be very useful to SAR teams, I suppose - unless you’re in a wilderness area where their use would still be illegal.