When the long gun registry came into effect in the early 90s in Canada, there was massive non-compliance amongst gun owners. Same with licensing. For obvious reasons its hard to come up with hard numbers, but I believe the government was guessing roughly 50% of owners never bothered getting licenses and registering their firearms.
Its funny to hear an American gun owner advocate for licensing and registration, when Canadian gun owners are fighting tooth and nail against that very thing. You need to recognize that once you've agreed to licensing and registration, your freedom to own a firearm is effectively gone.
Just recently the RCMP randomly decided to prohibit all CZ 858 and Swiss Arms rifles... overnight, with no warning. Owners of these guns are now in possession of prohibited firearms which are effectively very expensive paperweights. They can't sell them, they can't shoot them, they can't take them out of their homes. Luckily the outcry was big enough that the conservative government threw in an amnesty against criminal charges for 2 years until the issue gets looked at more closely. That's just one random example of what you're asking for loucypher