You could make the argument that with a strategic product like oil, maybe Canada would be better off having our own refining capacity rather than sending the crude to the Gulf coast refineries. It's not clear how Canada benefits by letting them reap the value-added profits. This is a bit like all those Covid PPEs that we were all scrambling to get a few months ago because no one was making them here any more. Sometimes, short-term "inefficiencies" are worth incurring for longer term benefits.
Although this sounds like a good idea, industries tend to consolidate in one location due to the support economy that develops there, and not being there just turns into a negative real fast. Being in the Gulf Coast just makes it much easier to be in the refinery business since everyone else is there, including already trained workers, professionals (lawyers, accountants, engineers, etc.) who cater to that business, suppliers (who probably have inventory in stock), investors, and everything else.
You really need a seismic shock for people to take the chance in another location, like what is happening with Silicon Valley. High taxes and high regulations that are abused by unions and then the shutdowns being the catalyst. Unlike CA though, TX is still a great place to do business and I doubt this will be enough of a hit to make it a better option to build a refinery in Canada as opposed to just continuing to send the oil down.
What gets me is that those on the left who do not have their heads up their asses know this oil will get to market and they also know a pipeline is the safest and most efficient way to transport it. Any other method is will use more fossil fuels of some kind to transport it and is of a much higher risk for a spill. It seems as though our environmental lobby just keeps on coming up with bad ideas just to satisfy their loudest and most uninformed members.
Of course this lunacy is not limited to just them; Trump is still touting his wall. This is why I am a small government guy. No matter what you do, as soon as government gets involved, nonsense follows. It's the same everywhere throughout time.