Canada doesn't maintain a military for self defence. If it did we would have pursued nuclear weapon ambitions in the 1940s and focused overwhelming on terrestrial missile systems and attack submarines. Even the interception routine of playing the games with Russian bombers at the edge of airspace is just meaningless theatre -- not only would those bombers long have deployed cruise missiles in a real conflict, the vast majority of devastation would have come from ICBMs launched by ground and sea.

In reality our peacetime military has been a welfare project to assist the US in whatever (mis)adventures it gets in around the globe. Our choice of jets, guns, vehicles, and so on is predicated on "when the US drags us into some conflict or other, what equipment integrates with whatever their goals are". So when we signed up for the F-35, that was purchasing criteria.

The world is quite obviously changing. If Canada were seriously interested in true self defence against all realistic foes, it would be nuclear weapons and nuclear powered submarines...like the sort the US blocked us from being able to buy from the UK back in the 80s.