I'm in the UK and would say it is the norm here - certainly if you buy a pre-packaged sandwich it would have butter (well, usually margarine) .
My sister's in-laws don't - my BiL's parents are both old enough to have grown up during the war and have always operated on a 'butter OR jam' basis (which when fat was very strictly rationed would make sense) and they have never broken the habit.
Spinning-off a bit, from the above: I recall a "mini-tale" once read, recounting doings in Holland centuries ago -- illustrating the renowned frugality and "economising" traits, of the Dutch. It concerned a father beating his son for spreading a piece of bread with butter, putting a bit of cheese on top, and eating same. "It isn't behaving in that way, that made this country great. You have bread with butter, or with cheese -- not
both !" I gather that in that part of the world, attitudes over this matter have become more liberal since then. (Dutch participants here, please tell me if the foregoing is a load of nonsense