Antonyms for the phrase "find use" would be "discard," "ignore," "neglect," or "waste." If something cannot be found useful or utilized, then it is essentially meaningless and ought to be thrown away or ignored altogether. Finding use implies that there is some value or benefit to be gained, so antonyms for this phrase indicate a lack of significance or worth. Sometimes, when we try to find use in something, we may realize that it is simply not worth our time or effort, and we must therefore decide whether to discard it or persist in our search for utility.