Unreliability is a cost. While the U.S. was the default, cheap and reliable option, it was virtually impossible to uproot settled patterns of behaviour. You just couldn't do the volume necessary to become competitive. That's changed. Also, transport is
far cheaper than it was when the old patterns were established. If China can become the manufacturing hub for the world, Canada can increase its reliance on the EU at the expense of the U.S.. So too can the EU increase its reliance on Canada.
I'm not speaking of some hypothetical future either. It's already happening. Watch the video.