Why does the US allow citizens to buy guns, but

The United States is a superpower. Not only has its economic strength ranked first in the world, but its military strength has been unmatched for decades. But the social stability of the United States has not been very good. Therefore, the streets of the United States, robbery with guns, shootings, etc., have been uncommon in recent years. In order to ensure the freedom and safety of citizens, the United States generally allows citizens to hold guns freely. But in this way, the crime rate will also increase. In the United States, it can be said that they are all soldiers. Basically, every citizen has his own firearms. Even if minors are not qualified to hold guns, they can still shoot with guns while accompanied by adults. The United States has had many cases of shooting violence because citizens hold guns, and many innocent people have been killed. But why not ban guns like we do? In fact, the United States is a federal republican constitutional country composed of many overseas territories including Washington, DC, 50 states, and Guam, and is also an immigrant country. Therefore, the internal personnel of the United States are more complicated and become a social instability factor, and national unity cannot be achieved, so turmoil occurs very frequently. To ensure the personal safety of citizens, allowing them to hold guns is the best option. Plus a big tax in the United States comes from citizens buying guns, so the United States does not intend to ban guns. But although the United States can't help but not allow guns, it is not allowed to buy body armor. In a few places in the United States, buying bulletproof clothing at will is a criminal act and will also be punished by law. In fact, allowing citizens to hold guns is already very difficult in catching criminals. If they still wear bulletproof vests, it will be more difficult to catch. Not only that, the police will even pay the price of their lives. In some areas, even if the purchase of bulletproof vests is allowed, light bulletproof vests can be purchased. High-performance bulletproof vests are not allowed to be purchased.