[yardstick]

> I think there is a legitimate argument that these arm rests are actually providing a useful service by delimiting the space for each person. Few people will naturally sit on the spot at the end of a bench seat which is already partially occupied (and other people will discourage it by sitting near the middle). Where as people will take an empty seat which is clearly free and separated from the other people on the bench.

Yes, exactly this! Especially when the platforms are crowded, it makes so much sense to be efficient on the allocation of seats.

Now we’ve still got to deal with some people bag-spreading but normally most people take their bags off as soon as it gets busy or someone asks.