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.