If you mean laws won't alter behavior and outcome, won't impact practices we view as destructive and violative of right, you're objectively, observably mistaken. By way of example, seatbelt laws and speeding laws have empirically impacted driving habits and saved lives.
It's equally easy to note that every state with the weakest gun laws here has the highest gun violence per 100k of its citizenry while the more stringent gun laws by state carry the lesser incidences. I've linked to those statistics in the 500 mass shooting thread, along with providing links and data on the dramatic disparity in gun violence and mass shooting here compared to our industrial-democratic cousins in Europe, where strong, universal gun laws are in place.
Laws can and do, in fact, prevent crimes. And in this case, at the very least, they can impact the degree of injury done and lives lost...In the case of guns it's not even that hard to see why. A man who is disturbed and angry within easy reach of an automatic rifle is much more dangerous and likely to harm a large number of people than is a man who is disturbed and angry and within easy reach of a hammer. We can impact how easy (and therefore how likely) it is for someone like that to harm a large number of people within a timeframe that makes it almost impossible to respond in time to stop him.
Laws are only as effective as peoples willingness to follow them. California has some of the strictest gun laws in the country yet they have had a terrorist shooting. FL had laws in place to prevent that shooter from getting a gun and the laws weren't followed and he got a gun. The Santa Fe shooter illegally took his fathers guns. The Sandy Hook shooter killed his mother and took her guns. New York, Chicago and D.C. all have very restrictive gun laws and equally high gun violence rates. Texas has less restrictive and less shootings. There was a shooting on a Naval base that has VERY restrictive gun policies.
In any case, our Canadian and European don 't see the same level of gun violence. Canada's laws are not as restrictive as Europe's but the violence rates are less. But they have other problems. Have you seen this picture?
It is a sculpture that is made from over 100,000 knives confiscated by the British police, knives that had been used in crimes. Gun violence may be reduced but overall violence is not. There was the bridge attack in London as well as the shooting and truck attacks in France.
I don't think that your stats accurately represent what we have seen in the shooting histories. I don't see where more laws are going to stop shootings completely. Everytime I ask people for a list of laws that would have prevented a shooting I get a list of laws that ALREADY exist in most cases.