Link I found for 2018 e-commerce net sales in Canada [0] has amazon and amazon.ca combined for 4.7b, costco at 1b, walmart 0.9, apple 0.79, the bay 0.47 etc.
So amazon eclipses the other other 7 competitors all on its own.
[0] https://www.statista.com/forecasts/871090/canada-top-online-...