It’s not the root cause, but I’m sure having easy access to a gun seems a lot quicker and cleaner than, for example, hanging yourself.
we’re getting into the macabre a little bit here but, to be brief: yeah. if it was required people attempt to hang themselves (or overdose, or any other non-firearm method of suicide), pretty much all the data i’m aware of indicates the suicide rate would drop appreciably from where it is now in the US (45,000-50,000 deaths a year).