"Crypto has legitimate uses like allowing people to use online banking. I can't think of a legitimate use a member of the British public might have for crack or an AR10."
That is, in part, because you live in a tame little country with no wild animals to speak of. There are places in the wilderness where I have been very happy to have an AR10 or its approximate equivalent, loaded with the heaviest bullets I could easily get.
My friend who got turned about, and ended up spending a night in the woods, feeding the fire and counting the eyes of the surrounding wolf pack felt somewhat the same.
So yes, I have the equivalent of an AR10, and the equivalent of an AR15, both locked in my gun safe. Both will do for wolves, but only one is suitable for large bear, though something more powerful would be advisable if you really expect to be out in bear territory.
Oh... and very few people buy AR10s - a bit light for bear, and a bit slow for a wolf pack.
Safety tip - for bear, look at a lever action carbine in .458 Winchester Magnum or 45-70 Government (modern high power loading). Clearing a misfire is much faster and simpler than with an AR10, and a bear won't give you much time.
While members of the British public don't have these issues at home, some of them do travel to more exciting places, and should therefore practice with the requisite safety equipment. Guns are tools, and where both my parents grew up (different places), part of the essential household equipment.