One other thing to add to this - Leslie from the article is likely a Canadian citizen, but a permanent resident in the same situation has a a very good reason for wanting to be able to maintain their ability to fly into the US. In short it makes it easier to return to Canada if you lose your PR card while abroad anywhere else in the world. See https://www.cbc.ca/news/canada/ottawa/ottawa-travel-nightmares-permanent-residents-1.7509870 and https://www.canadavisa.com/canada-immigration-discussion-board/threads/crossing-us-canada-border-without-pr-card.869083/