There are lots of categories for junk and, I agree, Americans are the world champions.

Lots of different categories of junk. Generally, there are the silly wasteful, there are the several increasing grades of harmful (to the environment from production to disposal), and then there are those that are insane. The prime category for insanely harmful junk is GUNS.

Europeans are vastly less junk-addicted (in both senses) than Americans. But one thing they kept from becoming the single most harmful bit of junk was GUNs.

If you think of harm sources in the USA (suicide, murder, permanent paralysis, limb loss, poisonous substances such as lead, etc.) guns are only outdone by automobiles in the USA.