Part of the idea of decluttering is that it makes you more aware about your possessions and that changes your consumption habit / buying behaviour because you become more attuned / aware of your mindset behind ownerships of things and how you value it. So you tend to think twice (i.e. properly evaluate) before buying something if you know you are going to throw it away it later. In certain cases, you tend to buy something second-hand rather than new (if it is for short-term use only) not just to save money, but to also reduce waste.
