> It won't help you with most killer avalanches such as large powder ones
This is tautological. Yes, few people survive killer avalanches, because that's what defines a killer avalanche.
Many avalanches encountered by backcountry skiers especially are not these giant killer ones, and can be survived either by skiing out of them or having the proper equipment and training. Your odds aren't great, but they aren't nothing either or people wouldn't bother carrying the gear. (beacon / shovel / probe / avy bag)
Anyways, this is sufficiently off topic, but your characterization of avalanches is movie-like-stuff. Huge avalanches happen but they aren't the typical case. Most are small / medium slides triggered by humans in the backcountry.