Useless or used-less?

Clearing useless things helps to make rooms for the new and to keep things organized. But for a reason, I rarely describe a thing as "useless". I used to do so, but turns out other people found the thing useful. This happens quite often. We actually didn't know how to use the "useless" thing.

The things that seem to be "useless" are used less. Interestingly, people use those things for new purposes. For example, leftover food kept for feeding pet dogs; empty plastic bottles used for making various household things; a broken light bulb modified into something for decoration; and an empty shoes box added with a magnifier glass for making a video/image projector for smartphone. Lots of other DIY ideas (in this webpage). Besides that, there are also other things.

Rather than a "useless" thing, it is just a "used-less" thing. And our "used-less" thing may become others' unexpectedly useful thing. So, it's how to make use of the thing.