More and more guns. We have the highest per capita rate of gun ownership of any developed nation on earth by a wide margin. That means there are more guns laying around that can be diverted to (stolen or sold) people who wish to do harm. This is emboldened by the last couple of decades of NRA lobbying to halt any meaningful gun legislation to protect people and a rise of the type of gun owner who fetishizes these things as opposed to using them as a tool.
More people had guns at home in 1980...gun ownership has dropped big time....... dipshit
GUN OWNERSHIP IN AMERICA: 1973 TO 2021
From 1973 to 2021, the percentage of American households that reported having any guns in the home dropped by
28 percent.
During this period the percentage of adults living in households with guns hit its peak in 1980, when more than half
(53.7 percent) of Americans reported living in households with guns. By 2021, 35.2 percent of Americans reported
living in households with guns, a drop of 18.5 percentage points.
https://www.vpc.org/studies/ownership.pdf