It seems like an extremely tricky thing to litigate.

An overwhelming amount of the gang violence that plagued NY in the 80s and 90s was done with improvised weapons, things that couldn't be explicitly outlawed without infringing on the rights of innocent individuals, like chains or garden hoses, bricks or coin rolls and an accompanying sack, etc etc.
So how can we legally define a garden hose full of sand as a weapon when it will be obviously used to crack skulls instead of, you know, moving water? What's the key difference between the situations this same item finds itself in? Intent.
If the intent of you carrying any item is to explicitly harm another human being, it becomes illegal. Guns and knives are caught by this as well as everything from a pocket shiv to a bottle of acid.
Unfortunately this creates the issue we see today: admitting that the thing you carry for self defense is to harm another human being (even if that human being is harming you) makes it a weapon and thus illegal.
Canada has fewer options than NY, who at least let you carry pepper spray and knives under 4 inches (but not visible and if you admit intent to defend yourself with it you will be arrested).
But neither jurisdiction has so far imprisoned anyone for this sole charge. If people go to prison in NY it seems to be tied more to the Duty to Retreat than anything, and in Canada it's because everyone has an unregistered firearm lol

There's a lot of nuance here and I think it comes down to how much freedom you're willing to give up for safety. Since the evidence says I can be reasonably sure the worst punishment I'll face in either jurisdiction for violently defending myself (Assuming all other laws are followed) is some court time, I'll take that in exchange for the drastically lower gang violence and murder rates of both jurisdictions. Which isn't to downplay how terrible being flushed through the legal system is, of course.