Do you mean like hoarders keberoxu? Or 'panic buying' in supermarkets?
People can be incredibly grabby sometimes. It may well be a primitive 'instinct' to seize everything possible to protect against hard times.

Attachment is difficult to conquer, I have some small ornaments I inherited from an aunt, and I treasure them. But they do clutter up the mantelpiece and I could easily sell them and put the cash in a charity box. I don't though, because I'm 'attached' to them. Maybe that's what happens on a larger scale?