AI systems provide many benefits to society, such as image recognition, anomaly detection, educational and programming used of LLMs, to name a few.
Guns only have a primarily harmful use which is to kill or injure someone. While that act of killing may be justified when the person violates societal values in some way, making regular citizens the decision makers in whether a certain behavior is allowed or disallowed and being able to immediately make a judgment and execute upon it leads to a sort of low-trust, vigilante environment; which is why the same argument I made above doesn’t apply for guns.