Honest question. Why do you need a gun (other than a hunting rifle), except to protect yourself from other people with guns?
To shoot hi-power metallic silhouette. (my .308)
To shoot small bore metallic silhouette (my target .22)
To hunt squirrels, rabbit and ground hogs (my other .22RF)
To hunt prarie dogs and groundhogs (my .17 HMR)
To hunt deer/bear/elk in good weather (my wood stocked 7mm-08)
To hunt deer/bear/elk in bad weather (my synthetic and stainless .257 Roberts)
To shoot sporting clays (my 12 gauge over and under)
To hunt upland birds with my lab (my light weight 20 gauge over and under)
To hunt ducks and geese (my synthetic 12 gauge pump)
To target shoot paper targets at the range (my .45 ACP)
To carry as a personal defence gun in the field (my .357)
To carry as a kit gun for plinking in the field (my .22 revolver)
To defend my wife, dog and house (my 9mm pistol)
To carry in the woods hunting small game (my .32 flintlock)
To hunt deer/bear/elk blackpowder season (my .50 Hawken or .50 in-line)
To destroy tin cans and targets in rapid succession (my M-4 in 5.56)
So that takes us about halfway through the safes. Why overall? Because I want to. Why do you need anything? Because I enjoy them and take pleasure in using them as tools to do a job. Same reason I have a 68" long tablesaw, because I can and I enjoy using it.
You need to investigate your irrational fear of inanimate objects.