In 2020, 54% of all gun-related deaths in the U.S. were suicides (24,292), while 43% were murders (19,384), according to the CDC. The remaining gun deaths that year were unintentional (535), involved law enforcement (611) or had undetermined circumstances (400).
Fear. Gun companies, the NRA and their suppoters (the republicans) know how to make people afraid, and to let them know that not only do they need a gun to keep them or their loved ones from being killed, but also that the democrats will take all their guns away and let them die.
Other developed countries have tight gun laws. Death rates far lower than U.S. https://www.bloomberg.com/graphics/2022-us-gun-violence-world-comparison/