Donning my conspiracy tin-foil hat:
These smart guns require an energy source. So in the event of an extended power outage, people would eventually lose the ability to defend themselves. Kind of like disarming them?
No need for confiscation just pull the plug.
A tyrant’s dream.
The Soviet Union used this same practice to control their populace. Every major city had heating plants, which piped hot water to the different apartment buildings, and the hot water was used in the circulatory heating systems. Shut off the hot water, and people got real cold, real fast.