Just cleaned out mt garage, closet, and attic. No clue why I kept every single box of anything electronic/tech based in the last ten years. I just tossed boxes for phones I haven’t had in years, old CPU and heat sync boxes, boxes for 100mbps nics, old modems I don’t have anymore. I’ve never needed any of these and have brought them with me through too many house moves.
I sell most of my old/used but still functional tech on ebay/craigslist. For very low resale value items (under $40) it makes no difference; but for more expensive resale value items, having the original box/packaging/manuals/accessories increases the resale value significantly. My auctions routinely sell for $30 more than comparable items.
It pays (literally) to keep the original box.