... which is more expensive than transporting by pipeline, thus increasing the cost of oil, cutting the development of marginally-viable oil exploration projects, and hastening the point at which it is uncompetitive with renewables and killed. This is working exactly as intended.
That said, running a refinery also has local costs that are usually externalized, in terms of local pollution and populace movement. Canada itself though has a fairly large amount of space, but perhaps a surfeit of people. Why doesn't TC energy (or other Canada producers) build a refinery somewhere in Canada and transport to there?
The only real lever the government has is increasing fuel taxes, but that would result in roots from people who are barely making it before massive increases in transportation costs.