There are large scale reasons decluttering helps society. We could talk about mass consumerism and the resulting waste and air pollution (think: Annie Leonard's "The Story of Stuff" video). While the subject of materialism and environmental degradation has immense merit, I wonder if you will take a short walk with me in a different, more personal direction?
Have you noticed the way your mind attempts to take inventory of the items that surround you? Can you picture a cluttered space? Maybe you are sitting in one right now. The excess might have any number of effects on you. Clutter might create in you feelings of: distraction, overwhelm, a desire to escape, or an urge to shut down. One feeling that might not come: peacefulness.
A beloved monk and 90 year old author says this about peace: "If we are peaceful, if we are happy, we can blossom like a flower, and everyone in our family, our entire society, will benefit from our peace". - Thich Nhat Hanh
Wherever you are at this moment, reading these words, I suspect you want peace in yourself, peace in your nation, and peace in the world. Decluttering certainly cannot fix the deep divides in the US. No, America's problems will be fixed by community organizers spreading messages of love and acceptance, and law makers heeding those messages. Taking steps, however, to remove things from your life that no longer serve you can help you find at least some degree of internal peace. As Thich Nhat Hanh gently reminds us: when we have peace, we can spread peace out into the world.
Go forth, my peacemaking friends!