The headline difference: spray foam air-seals AND insulates in one step and holds its R-value long-term; fibreglass (fiberglass) is cheaper up front but doesn't air-seal and can lose effective R as it settles or gets damp. In Alberta's cold, the air-seal is where the savings live.
Air-sealing is the real gap
Fibreglass batt slows heat by trapping air - but it does nothing to stop air moving through the gaps around it, at outlets, top plates and rim joists. Spray foam fills and seals those gaps, so the wind stops driving cold through the wall.
R-value that lasts
Spray foam is rated on long-term thermal resistance (LTTR) - it holds its number. Fibreglass can settle, sag or absorb moisture and lose effective R over the years.
Cost vs savings
Fibreglass wins on upfront price. Spray foam costs more but returns it through the air-seal - especially over a long Alberta heating season. Where does fibreglass still fit? Big open attics on a tight budget, or assemblies that don't need an air-seal.