This thread suddenly reminded me that I have not recently put random items into a normal bag of holding. A normal bag of holding found by adventurers should almost always have a bunch of other stuff in it, including other magical items (mostly potions and scrolls, but potentially non-consumable items). It's not like bags of holding are crafted and then never used, just to be found by someone in a dingy old dungeon somewhere.
Ditto for Portable Holes, Haversacks, etc.