Ontario’s Health Care Consent Act has been on the books for nearly two decades. Like similar laws in many Canadian provinces—and American states—it sets out the process for making treatment decisions when a patient cannot provide or withhold her consent—when she is in a coma and on life support, for example.

America has them too. The above is from the same Slate article you linked.

Maybe don’t just pick and choose portions of an article that match your confirmation bias.