Trim it down to one of each cable. You don't need a half-dozen patch cables. That weird wall-wart with the proprietary DIN plug for the laptop you no longer have, or the voltage- and milliamp-specific application you'll never need. The 4 SATA cables...etc.

Pare it down in order of likely need. You might need a couple USB cables and maybe a couple SATA cables, but you don't need 3 34-pin floppy drive ribbon cables.

Yes. The correct approach is to get rid of all the cables that are not needed, and to keep the few cables that might come in handy. Throwing away a collection in bulk is risky.

I took the middle road: use cable zip ties to bundle them and put all in a bag. Since finding a cable is infrequent, you don't need to optimize for that case.

I have plenty of duplicate cables. Pretty sure I don't need all of them so I can throw out most of them and just keep one of each.

Pretty sure I don't need a SCART to VGA cable but doesn't take that much space up.