This fact is unpopular among pro-gun people, a significant portion of the american populace, and runs counter to their narrative that more guns make society safer.

Anyways, whenever someone mentions that guns kill X number of people every year, there's always one person to says "well actually, most gun deaths are a result of suicide". This response is a pretty bad one.

Why is this the case? Because the prevalence of guns is significantly correlated with suicide. Experts overwhlemingly agree that the presence of guns increase the risk of suicide and that more guns in general do not make society safer. The Harvard injury control center has a good page on the topic, with research conducted by David Hemenway.

Additionally, from Cook and Goss's 2020 book (The gun debate: what everyone needs to know):

Teen suicide is particularly impulsive, and if a firearm is readily available, the impulse is likely to result in death. It is no surprise, then, that households that keep firearms on hand have an elevated rate of suicide for all concerned—the owner, spouse, and teenaged children. While there are other highly lethal means, such as hanging and jumping off a tall building, suicidal people who are inclined to use a gun are unlikely to find such a substitute acceptable. Studies comparing the 50 states have found gun suicide rates (but not suicide with other types of weapons) are closely related to the prevalence of gun ownership. It is really a matter of common sense that in suicide, the means matter. For families and counselors, a high priority for intervening with someone who appears acutely suicidal is to reduce his or her access to firearms, as well as other lethal means.

For some additional sources, look to this GMU Study by Briggs and Tabarrok, which find a significant correlation between prevalence of guns and suicide and this study which looks at firearm availability and suicide.

So it's clear that the means by which people commit suicide matter. Dismissing 2/3 of all gun deaths as suicides in response to people mentioning gun deaths is a bad argument, considering how much of an impact guns have on suicide rates.

Credits to u/Revenent_of_Null, whose comment I got one of my sources from.