I've seen this mentioned, but there are even more basic problems.
Let's say someone wants to make "smart scissors". You have a very basic device with 2 pieces of metal that slide against each other when the handles move. But now we have to stick a chip in the middle of this somehow. Do you need to worry about it breaking when you cut something really hard or moving the handles too fast? Electronics tend to be more delicate than pieces of steel. What if the battery dies while it's sitting in a drawer because I haven't checked it in a while? Do the electronics damage if you drop it? Guns are jolted every time they are fired. Not to mention the heat, fouling, and cleaning/lubricating supplies. And obviously you need to validate somehow. How reliable is that mechanism? Keep in mind guns typically have textured grips that the owners like to replace so I don't see fingerprint scanners working. RFID like the Armatix smart gun? So I need to worry about jammers?
Nothing about smart guns sounds like a good idea.