Stock markets crash. Collectibles crack, chip, tear, fade and break. Toys lose their attraction and collect dust. Termites eat books. Businesses go bankrupt.
Thieves help themselves.
Vandals make mayhem. If we have nothing greater to value, then stuff of earth seems valuable and important indeed. Once we have tasted the things that really amount to something, the most enticing things here seem quite dull and tinny. Those who live for any of these things naturally lay up treasures on earth. Those who live to prepare themselves and others for eternity have limited place and patience for temporal mirages.