Okay yeah sure, it can and does happen on occasion, but how often matters a lot. We can't just ban everything over every rare and unlikely scenario, and it will still do basically nothing to stop 99.9% of gun crime. Plus from when the CDC was allowed to research such things, they found between 500,000-3,000,000 cases of defensive firearm use per year in the US, 2-10x as high as violent crimes.

Maybe you live somewhere privileged enough that you can rely on the police to protect you, but most of the US doesn't. For many people in the US police response is 30+ minutes, and the police themselves pose as much of a threat to them as the criminals they are calling about if a potential danger.