It's also politics. If you actually wanted to solve the problem, well, like two thirds of US firearms fatalities are suicides. So a real solution is going to look like "improve mental health" and not "restrict who can buy a gun" or else you're only going to be diverting people to other methods of suicide, or keeping people "alive" but still in such a precarious mental state that the only thing preventing them from taking their own life is access to an effective means. Neither of which is actually acceptable.
But from a political perspective, proposing useless gun restrictions makes the other team have to spend political capital to oppose them, because even if they're completely ineffective at their stated purpose, they upset or inconvenience the other team's constituents. Which seems to be the goal of modern US politics.