All down to standardisation of size. Did you see the News program the other day visiting their new distribution centre. All automated with the system deciding what goes where and when. The box size is chosen. My local courier told me that they do not use small boxes as they get lost and economies of scale dictate the sizes used.

I also buy from RS Components and they deliver each item in a white bag packaged in a bubble bag and then all enclosed in a larger bubble bag. You can order up to 10pm and it arrives first thing next morning ( might be because I am adjacent to an M6 junction).

If you have friends who are moving the Amazon boxes and paper are ideal for packaging small items.

That's Amazon for you I had a similar one not long back but with a tin of Evo contact adhesive (other makes are available) when the box arrived I couldn't think of what I ordered that needed that big a box but they never but any protection under the goods they are always at the bottom of the box under miles of brown paper?
It's OK its all recyclable!