Yeah I agree with how this sounds really not useful, but wardrobes are a nice idea and I think it wouldn't be too hard to think of a more a unique function for them.
Two ideas I came up with are, you can store a single Loadout inside a wardrobe, and clicking on the wardrobe will switch your loadout with what's inside. So it'd be like extra placeable loadouts that can also be used by other players, could be convenient for maps.
The other idea I came up with is just that they work like dressers in Stardew Valley. You could store an infinite amount of armor and vanity inside them, but they would all share the same player inventory, like a piggy bank. This would also be useful since armor and vanity sets tend to be annoying to store since each setpiece takes up its own slot. Only issue I see with this idea is they'd probably have to implement a new UI for that.