Bulletproof clothing only protects you against bullets (well it protects against knives too but you can buy less expensive slash/stab resistant clothing). In Australia there is virtually no gun violence. The only people who can shoot you are cops. They will only shoot you if you're doing something that justifies being shot at. Therefore, the only reason you'd need bulletproof armor is if you intend to do something that would justify the police shooting at you.

Encryption on the other hand has legitimate purposes. It's quite possible for someone to say steal all your money by intercepting your bank account login and it requires no special, heavily restricted equipment to do so.

In reality, law and society are complex creatures. I'd observe that any knowledgeable person observes encryption is commonly and widely used for a variety of purposes, and has many people who will push back against its denial of use.

In terms of the body armour law, there would presumably be the empirical facts that:

1.) There's just not actually a demand for it amongst the society in the aussie context at least.

2.) The odds of being shot or stabbed by someone other than a close relative is virtually nil in Australia if you're not partaking in a criminal enterprise. And so far as long as those criminal enterprises don't spill over into public related injuries and violence, people's level of fear regarding guns/stabbings is pretty low.

3.) This must be taken in the context of an everyday culture that has a rate of ~1 in 100,000 rate of homicide (non-uniformly distributed admitedly) compared to the united states rate of ~4 or 5. The culture is relatively uniform, and united states-esque laws and policies regarding weapons and obsessions with are generally viewed as a mixture of "crazy", "a warning of what we could become", and just a generally undesirable state of affairs.

There is a debate regarding encryption. Whereas debate around things like increased access to weapons or body armour is "effectively zero" in the context of Australian society (keeping in mind I don't have the time/space to go into the historic details or rural hunter/fisher/farmer politics).

I'm going to assume that canadians in many ways view american laws/society in a similar vein to us in this context: our friendly but crazy relatives. (albeit with them sharing a physical border).

I'm also guessing (I haven't looked it up) that they have a far lower homicide rate, and would suggest, like Australians, that they believe de-escalation and keeping militarized equipment out of the hands of civilians primarily provides a greater civil protection against shootings/stabbings than ownership of body armour would.

Now, to not be objective for a second, i think real life is more complex, but empirically, given the relative differences in homicide rates, i'd say the American case at least appears to be starting the argument on the backfoot :)