Its not All or nothing!
Its a balancing act.
I'm on the lean side , due to lack of space . 2 boxes of cables (scarts and other older ones have been chucked) 1 box vinyl . one shed containing a dismantled car that is the same model as the one i drive .
1 box misc pci cards etc
You have to weigh up the odds of someone wanting to pay you money to show up with a parallel floppy drive that only works in xp against the cubic inches it takes up.
We all wish we had a magic shed like the Tardis... but most dont.
Software ans files on the other hand.... hoard as much as you want! Hard drive storage is massive and so cheap you can keep anything! (within reason)(a 100 disc blu ray collection is not "within reason" - keep that on tye discs it came on)