Guns are, at least, part of the problem, mainly because the NRA is a powerful lobbying machine that keeps our congress from passing even reasonable gun laws. Hell, shortly after the 2017 Las Vegas shooting congress had to sideline a bill they were caught running through that was pro NRA. After 58 people were killed and 422 were wounded they showed us who they are working for, and it's not for the safety of American citizens. Sick bastards.
Mental health is also an issue. Partly because nobody gives a crap, and partly due to states being strapped for cash. Ronald Reagan showed us how much republicans care about the mentally ill back when he was governor of California, and studies consistently show that their states have some of the worst mental health care in America. Ironic that they always point to mental health care on all gun issues yet don't give a crap to actually get their politicians to work on shifting more money... to mental health care.
Sadly too many people post the same tired old talking points yet don't take any action. These people are also part of the problem.
I could go on all day, I will leave it here though as it covers the main two issues that always come up in these discussions.