Peter Zeihan makes the case in one of his books for why Alberta should leave Canada and join the US. I’m not Canadian or American and have no dog in the fight, but it’s interesting reading.
While Alberta is often called “the Texas of Canada” there is not a single Albert a that would give up their healthcare to join the US. In many meaningful ways their standard of living would plummet overnight - healthcare, education, safety, violent crime, life expectancy, etc.
I think it's reasonable to presume that any territory added to a country will become the average of that country over time.
So the better question is actually why is the average American such a violent criminal compared to the average Canadian? Answer that and you will have answered your question.
Likely lack of healthcare (desperation), lack of affordable education, debt, need to fill for-profit prisons, corporate lobbying to make regular people's lives worse, etc. etc.
> Violent crime in the US is not evenly distributed.
Neither is it in Canada.
If you want to cherry pick the "best" of the US and leave out the worst from any comparisons, you'd have to do that for whatever country you're comparing it to.
Interestingly enough while the Canadian constitution doesn’t flat out permits this, it does allow the province to have a binding referendum and should a vote come to pass by it’s people, it forces the federal government to seriously consider it, thus a faithful negotiating can take place which could lead to the province becoming a sovereign nation.
While Alberta is often called “the Texas of Canada” there is not a single Albert a that would give up their healthcare to join the US. In many meaningful ways their standard of living would plummet overnight - healthcare, education, safety, violent crime, life expectancy, etc.