I do keep the box for whatever the most recent Xbox I've bought is, foam inserts and all, started doing so with the One. So right now I have an One S box in my attic. I do this because it makes it a lot easier to pack up the console for transport. In the before times my friends and I would get together ~ once a year and have a big LAN party at one of our houses, Halo and Gears and that, so it was good to be able to pack up the console reasonably securely, pop it in the back of my car and not have to worry about it sliding around or breaking.
I do not still have the box my PS4 came in, when I get a PS% I won't be keeping that box either, still undecided about the new Xbox box, Series X could probably just slide that bitch into a backpack and stuff towels around it.