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.
This is the big reason. I keep the boxes to make future moves easy, learned the lesson the hard way.
Other good reasons are the box keeps all the accessories in one place while saying what they are for (psu boxes, looking at you) or the box is great at storing that type of item, like the box my NAS drives came in, perfect foam insert for other drives
I moved last year and tossed a bunch of boxes. But those that I kept and used in the move were for my most expensive electronics and I'm glad I did. As usual, the packaging that can withstand shipping halfway around the world was a perfect match against the somewhat incompetent movers that I hired. Mistakes were made, but none of my gear was damaged.
Well, I for one am sad I threw out my 90s hardware years ago, including things like a Voodoo 2, Voodoo 3, AWE32, AWE64, SB16 ... those things are really hard to find nowadays if you want to build a retro PC.
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.
Lol - I had the same problem for many years, until I finally decided to clean them out like you did.
My policy now is to keep them for a month or so before tossing them. That's arguably when they're most likely to break down and I'd still need to ship/take them somewhere in their original packaging.
It's because when you first buy the thing, you don't want to get rid of the box right away, in case you need to RMA it. So it gets put in the pile along with the rest of the boxes. Then you're in the same place for years and the pile gets bigger.
I do a decent job with culling the boxes, and even toss obsolete tech now and then, but I have been hoarding hard drives for 30 years. It seems more trouble to securely dispose of them than to just let them pile up. I even still have IDE drives and am not quite sure whether I have an adaptor that can read them. But I can't throw them out, because I don't know if I have sensitive info on them.