I see those boxes at estate sales regularly. And on FB marketplace for free or $5. Or sometimes somebody thinks they're sitting on a gold mine of technological history and tries to ask actual money for a box of 20 year old tangles.

Sometimes hoarding stuff pays off. It's usually just hoarding.

It think it's both. The more stuff you have, the more you hoard, and the less you need to pay in terms of time/energy/money to get something you had in the past if you need it now/later, and on the flip side, you can be more minimalist, and will need to spend more time/energy/money to get the things you threw away/gave away/sold if you need them now/later.

It's mostly a resource/constraint time/space/money/effort problem.