It doesn't exist because the politicians decided (with the help of the person with the patent) to force it on the public by writing laws that said they all had to have this tech when it became viable.

In addition- just as with airplanes- when your life is on the line if a thing doesn't work, you're very conservative about change (oh please add a battery and electronics...)

Third- it doesn't solve a burning problem- if the market wanted it and without #1, it would be available.

What issue is smart guns really going to solve? In a venn diagram where you have people that are irresponsible with firearms that cause accidents and people that would buy a smart gun I suspect the intersection between the two groups would be negligible.