"Not everyone follows laws, so why bother having them" is a pretty bad argument. You're right that pretty much no law can be 100% effective, but if you want to

"Not everyone follows laws, so why bother having them" is a pretty bad argument. You're right that pretty much no law can be 100% effective, but if you want to reduce gun violence, reducing the number of legal firearms is certainly one of the ways to go about it.