Before I begin, I need to share my bias: I own many different types of guns, and I'm firmly of the belief that a well-armed populace is essential to combating fascism, especially nowadays, when the ground we walk on is filled with the seeds of fascist ideology.
Mass shootings are completely unacceptable failures of our society, and they're largely unique to the US. I'm of the opinion that the wealth disparity is connected to these shootings. Ultimately, most of these shootings are a particularly violent methods of suicide. If we can find a way to reduce and prevent depression and suicide, I anticipate it would lead directly to a reduction of mass shootings.
Many people are facing a desolate future: between wealth inequality, rising cost of living, stagnating wages, no access to affordable healthcare, substandard public education, astronomical costs of higher education, the plague of racism and bigotry at large, climate change, war, social media, and any number of other nightmare-inducing systemic failures of the western world, well… it's not exactly surprising that "deaths of despair" have been rising sharply. If I recall correctly, deaths of despair (suicide, drug overdoses, alcohol poisoning) were so numerous that they accounted for a DECREASE in life expectancy in the US last year.
What we need to solve this problem doesn't start with gun control (not to mention the debate on whether or not gun control can even be executed in the US effectively), what we need are direct and measured changes to our government and society at large. The capitalist system has proven its effectiveness at generating a profit, but it has shown itself to be weak to systemic problems that can't be solved in a profitable manor. I reckon that if we can restructure society to be more equitable at large, we would see significant drops in gun violence, deaths, and mass shootings, even if no changes were made to gun laws whatsoever.