Do note that enemies can also pick up that old equipment and use it against you. I lost a promising character during the last November NetHack Tournament [1] because a gnome picked up a wand of fire from someone’s grave and blasted me with it.
Yeah that’s another difference. When you play NetHack online [2] [3] you run into the ghosts and graves of other players, not just your own previous characters. I have run into levels online with the ghosts of 3 different people who were all killed by various dangerous monsters that kept accumulating more powerful equipment from each victim. It can be quite ridiculous!
[1] https://tnnt.org/
[2] https://alt.org/nethack/
[3] https://www.hardfought.org/