Not all.
Only the ones that will matter someday.
My older S&W, Colt, Winchester, and Browning boxs, and a few others, are wrapped in plastic and have a safe place in the basement.
Most of the more modern and less collectable stuff went in the trash eventually.
I usually keep all boxes for a while, until I decide if the gun is a keeper or not.
Not sure why though.
My kids will likely throw them away someday when I'm gone, and I'm not selling the guns before then.
rc