It does fit the definition of an oligopoly, which is where the controlling share of a market is held not by one company, but by a few companies. I don't think there's any question about that.
Is it competitive? Oligopolies do compete with each other. There's no doubt about that. They compete with each other in particular, limited ways that don't necessarily conform to the assumptions of competition as it's taught in economics textbooks.
There's not a black and white spectrum between competitive and non-competitive. There are ways in which they compete with each other, but there are ways in which they clearly don't.
I do think that the fact that this industry is so concentrated does help to explain why its profits have remained at these elevated levels postpandemic, while other sectors in Canada have seen profits retrenched towards pre-COVID norms.
As some of those initial inspiring factors that cause the inflation—things like supply chain shortages and even energy prices—start to abate elsewhere, that has led to a slowdown in inflation and reduced profits. In the food retail sector, profits continue to grow. That is an exception.