The refineries are in Texas, and Canada doesn’t want them built in Canada.
Canada is not without its refineries.
The issue is: Where are the refineries that can efficiently distribute finished product to the markets which will use them?
The answer to that question is: The Texas Gulf Coast, which has a network of finished product pipelines serving most of the USA.
Canadian refineries don't have an existing finished product pipeline network to distribute their output outside of Canada.
Wonder why Canada doesn’t want to build refineries?