For the past few years, we've been "getting smaller" by getting deeper. The diameter of the cell shrinks, but the depth of the cell goes up. As you can imagine, that doesn't scale very well. Cutting the cylinder diameter in half doubles the depth of the cylinder for the same volume.
If you try to put the cells closer together, you start to get quantum tunneling where electrons would disappear from one cell and appear in another cell altering charges in unexpected ways.
The times of massive memory shrinks are over. That means we have to reduce production costs and have more chips per computer or find a new kind of memory that is mass producible.