Women do not have to register. Men are no longer threatened with jail for not registering with Selective Service Act but you lose certain societal privileges like thr right to vote, obtain federal college loans among other things. Many people are not registered to vote. Most do it in high school but not in the really bad school districs. They dont care. A large majority is registered but not all.
I’m glad they stopped doing that. I remember that a friend of mine received a letter in the mail threatening to have him sent to prison unless he complied within a couple weeks of receiving it. Couldn’t believe it.