From Longman Dictionary of Contemporary Englishwhat’s the use (of something)what’s the use (of something)spokenPOINTLESS used to say that something seems to be a waste of time What’s the use of decorating the house if we are going to sell it? → use
Examples from the Corpus
what’s the use (of something)• My granda is dying there and what's the use?• And what's the use of being on observation when you can't observe anything?• You're a bloody animal, Cullam, without an animal's ... Oh! what's the use? 