The NJIT got a grant from Taurus to work on a smart gun. I knew a guy who was involved. It never worked well enough.
It would be disaster for a military, police or SD gun. Why it might not work at the same rate as the 1911s in an IDPA match - hahaha! I can say that as I'm shooting mine tomorrow if the weather does screw us up.
For a hunting or target gun - then it's a market decision. Mandating them is what evil folks want. Some gun companies wanted that too - it was suggested that if it was mandated then Colt would have had a shot at the police market. All police guns would be obsolete and there would be huge market for the new smart replacements. Their first Colt competitor and the basis for the smart gun was the Colt 2000 - which was a disaster.