be no good to man or beast
To be completely useless; to serve no purpose; to be unsuitable to anyone or anything. I admire the intelligence with which you argue your points, friend, but unless you're willing to put your words into action, I'm afraid your philosophizing is no good to man or beast. After 20 years, my faithful old truck finally broke down for good. It's no good to man or beast anymore.
be no good/use to ˈman or ˈbeast
(informal) be completely useless: Since the Chernobyl disaster the land round here has been no use to man or beast.