At least in the US, a majority of deaths by firearm are suicides. And as for potentially addictive drugs (e.g., alcohol), the user can cause great harm to other people, as in drunk driving.
[1]https://www.pewresearch.org/fact-tank/2019/08/16/what-the-da...
Fivethirtyeight says about 2/3 of gun deaths are suicides. Around 1/3 are homicides. A surprisingly small percentage (to me) are classified as accidents.[0]
The amount of people who know nothing about guns and never shot one under proper supervision and then go out and purchase a firearm without researching anything are extremely low, so accidents remain pretty low.
There are some guns for which the basic dogmatic instruction is probably insufficient. Notably glocks; in some circles "glock" has become a verb, wherein to "glock yourself" means to accidentally shoot yourself in the leg with your glock while holstering or upholstering it. More specialized training can reduce the chances of this happening, but for this specific scenario and some others like it, the standard basic safety instructions fall a bit short in my opinion.
[0] One example: http://www.rcmp-grc.gc.ca/cfp-pcaf/safe_sur/acts-tpto-eng.ht... Other rulesets often have the same ideas worded in slightly different ways.