One human product that is considered useless to most human beings is the "Pet Rock." The Pet Rock was a novelty item that gained popularity in the 1970s. It was essentially a smooth rock packaged in a small box with holes for ventilation, straw for bedding, and a humorous instruction manual on how to care for your "pet."
The idea behind the Pet Rock was that it required no feeding, grooming, or attention, making it an easy-to-maintain "pet" for those who didn't want the responsibilities of a real animal. Despite its simplicity and tongue-in-cheek concept, the Pet Rock became a short-lived fad and eventually faded into obscurity.
While it was a fun and quirky idea, the Pet Rock ultimately served no practical purpose and did not provide any significant value to human life.