To profit, they would first have to sell the goods. Who is actually in the market for a smart gun? Consumers aren't, surely. There is virtually no upside to your gun tracking you, at your own expense of buying a more complex piece of tech to boot. So that leaves something like (apparently) New Jersey where the government would compel purchases of smart guns because they were interested in the tracking. But eg. China simply don't allow citizens to purchase guns period. There may be some application to applying it to state-owned firearms to track military and police usage, but deploying that at Chinese scale would be an extremely expensive endeavour for what appears to be a solution in search of a problem. Not to mention the biometric lock concept, if implemented, is introducing an entire new axis of unreliability to a life-or-death tool.

I could not locate credible evidence of a major firearm manufacturer that completely refrains from selling into the U.S. civilian market. (ChatGPT)

Glock, Koch, Taurus, even Czech Zbrojovka all sell to US.

Kalashnikov can’t atm, but also probably doesn’t share the safety concern.