Any law, at any level of government, should automatically be revoked if there hasn’t been a successful prosecution under it for a certain period, say ten years. Whether it proves impossible to convict a violator, or whether the law simply gets overlooked, either way it’s a useless law.
I remember years ago reading an article about old arcane laws. The one that cracked me up the most since I was a fairly young driver was the loss still on the books that required any automobile entering the town to be preceded by a certain distance by someone waving a red lamp, apparently to warn the townsfolk.