I've tried that, but I accumulate more junk...
I know the feeling, but sometimes you just gotta hit "purge." I sell most of the Macs I receive for free (and I only ever purchase them to repair and resell them), I've gotten rid of every book I owned that wasn't a reference book or a really good novel, my classic Macs are in the closet, my stray papers have all been put in binders, my spare computer parts collection has been slimmed down greatly, and I still have more work to do. It does help that I don't make impulse purchases (except maybe cheap food), but idk if that's your problem or not.
Obviously I don't know your needs, and I can't really speak for you, but I can't see why you'd need more than just the MacBook on the desk. _Maybe_ the PowerMac as well, but then doesn't it get annoying syncing data across computers?