Claimed identity isn't a suicide pact and consent of the governed isn't equally geographically distributed.
AB sees, correctly, an inordinate amount of tax per capita go out for the privilege of policies intended to kneecap that region's development. The justifications for those policies (whether you agree with them or not) matter less than the fact they're being imposed from a condition of moral hazard.
Hence, the people of AB might vote to ban the people of ON/QC from imposing their laws; that's what separation is and why it happens.
Not only that, but the Feds typically use their outsized tax revenue from Alberta to “invest” in Quebec to buy votes via propping up unviable businesses, subsidies, outsized proportion of public sector jobs, and federal spending in general.