If you always thought indicator lights on a BMW are the most pointless things out there,

Are we talking about the grippy socks or the child’s legs? I’d say both are useless that early on

Those socks are for when the baby learns to stand up. Or they began to crawl.
My daughter when she was crawling never crawled like a normal baby. She did what we called her monkey crawl. Where one foot was like the normal crawl but she tuck the other where her knee be in her stomach and her foot would be flat on the floor. She would push off on that one foot and drag the other. These type of socks helped her a lot.
So they are not for newborns unless your new born happens to be a rather big baby.

If you want useless just remember that the Nokia 3310 came with a warranty.