I've been researching voiceprints, Kaldi, and speech-recognition in general, and stumbled upon this gem. It's clear that voiceprint is going to be around for a long time to come, because it sits in a sort of "Goldilocks zone" of the ease-of-use vs. secure spectrum in several ways. Look at this chart, and see if you don't agree:
This is an image from an article... hmmm..... [rustle rustle paper rustle].... erm.... I just spent several minutes looking for... and cannot find at the moment. As soon as I find it, I'll update this post with the URL for the article.