In the United States, adult males have to sign up for the Selective Service for the same reason even though we haven't had conscription since the Vietnam War in the late 1970s(?).
> Annual budget $31.3 million (FY 2024)
If it hasn’t been used in 50 years, is there some other use for the registry or the organization or why hasn’t this been cut yet?
I don't know how it worked for anyone else, but I remember the selective service PSA ads when I was growing up -- (that's a manual emdash) If you don't sign up for selective service when you turn 18, you'll be celebrating your birthday at pound-me-in-the-ass federal prison. Or maybe you couldn't get a welfare check, college loan, or federal job. The details are a bit fuzzy.
Then a month or two before my 18th birthday, I got a postcard saying I had been auto-registered. It was a rather disappointing denouement.