Dont justify after the fact just dumbly implement the rule.
So $20 fee to pay for getting rid of a bunch of other cables I didn't need years ago and saving ~500 cubic cm of space.
And I gave the printer cable away to a friend when I was done with it, happy to repurchase it in a few years in the increasingly unlikely scenario that I need it again.
Keep a few extra cables of sorts I actually use fairly often (a few spare HDMI cables, some ethernet cables, and a few types of USB cables are no-brainers, for instance). Toss all the rest (am I ever, ever going to use a DVI cable again in my life? Decent odds, no, and on the off chance I do I can just buy another)
Any cable that's more than ~2 spares for a port on some device that is plugged in or otherwise in-use in your house, or isn't a kind of port you've used in a couple years (even if you could) should at least get some serious scrutiny and more often than not be donated or go in the trash.
Like, I held on to a couple coax cables more than ten years after the last time I plugged anything into a coax jack. So stupid, in hindsight.