Why buy margarine in the first place? Margarine seems to be more prominent outside of the U.S. There's usually only a few brands of margarine on American groce

Why buy margarine in the first place? Margarine seems to be more prominent outside of the U.S. There's usually only a few brands of margarine on American grocery shelves but in Canada there's a whole wall of margarine next to a small shelf of butter. It seems very strange to my American eyes.