Why doesn't my hopper put drops into a chest? [closed]
The hopper is probably not attached to the chest. You have to right-click the chest with the hopper in your hand to place the hopper and connect it to the chest.
You can right-click the hopper onto the chest by crouching while you right-click. Since right-clicking a chest normally opens the chest and the crouch-right-click trick is new, people don't try it, and they get non-functioning, unconnected hoppers sitting beside chests.