Here’s the thing. I’ve got at least two family members that could probably be classified as hoarders. They keep a bunch of stuff that they really should get rid of. But at least part of this is, I believe, ingrained upon them by their relatively impoverished upbringing. They would hang onto items of marginal value because that marginal value means more when you have to scrape by.
Decluttering is a luxury. Rich people can throw out their rarely-used junk because it’s trivial for them to buy new stuff should the need arise. Poor people keep the “junk” because that little bit of potential residual value is a part of their livelihood.
Most people should put their stack of National Geographics in the recycling bin, because it isn’t worth their time to find the person who’ll give them five bucks for it. For some people, that five bucks matters.