I'm mostly talking about Micro USB cables; they were pretty notorious for gradually becoming loose.

They definitely wouldn't be a great fix and could potentially make things worse but for electronics you don't plan on unplugging again or mind dying shortly after I could see them coming in handy if you don't want to solder on a new connector or rely on strategically placing a device where the cable makes proper contact. I could see them being a weird item you stumble across on Ali Express.