Also note that the embedding of the Right of The People to keep and bear arms is specifically intended to allow them the only means of countering tyranny when peaceful means fail.
How many countries understand it may one day be necessary to kill their own government and protect the potential of their citizens to do that?
Further, weapons exist in sufficient quantity in the US to make a popular revolt viable as the number of armed citizens utterly dwarfs the number of police and government and military functionaries, which groups would be divided in a serious revolt.
England has a few people with a few weapons, but they don't matter and the people there have long surrendered even more of their rights to their government.
Americans are indeed fat, uneducated slugs by and large, but if our masters one day overstep their bounds the Founders ensured we have a viable chance of killing them and taking the country back.
The tiny firearm crime rate among people who aren't garbage is a modest price to pay for that. There being no viable self-defense against a physically superior opponent without firearms, guns are also key to personal security in many areas.