"except anyone resident in Quebec, Nova Scotia, Yukon, or Ontario"...it is essentially 75% of Canada!
Quebec is a different matter; far more complicated to calculate payroll deductions for there.
Imagine the complications of moving back and forth between provinces. Or seasonal work, etc.
Another example is Quebec sitting on a gargantuan natural gas reserve, but preferring to keep it in the ground because it's more advantageous to simply receive payments from other provinces (Alberta). Carbon/emission considerations aside, this shows just how broken the incentive structure is for equalization payments between provinces.
But that's just the tip of the iceberg as far as Canadian governmental issues go, and it's hard to know where to start improving things.
This seems like a massive thing to just throw aside.
Meanwhile Alberta burns (and leaks) natural gas and coal and gripes because the rest of the country is punishing them for it, and complains to high heaven that we're not making new markets for them (or others) to burn and leak more of it.
Quebec and Ontario have prioritized manufacturing over resource extraction, and that benefits their population.
But there is no Free Trade between Provinces (Inter-Provincial Trade). Canadian Provinces have more Free Trade with the USA and Mexico than they do with each other. Canada isn't really a country in the economic sense. And aren't there restrictions on professions like Engineers and Nurses such that you can't just pick up sticks and go to work in another Province? There's bureaucratic paperwork to fill out before you are good to go.