Though different terms are used, both SpatialOS and "Age of Ascent" specifically reference the notion of "Interest Management." That is, not only do the online servers have to simulate the world at the rate of game ticks, the online servers also have to calculate and generate timely updates to interested parties and compensate for lag while seamlessly distributing load across the cluster.
The hacks that Eve Online used to somewhat do interest management resulted in metagame "Grid Fu" -- https://www.youtube.com/watch?v=N8K18S_RNEQ
3D worlds are really good for interest management, since distance between objects generally means a drastic lowering of bandwidth required between the objects, even though the objects are still visible to each other. In 2D, such objects have zero bandwidth, but this means there are no "vistas" unless the view zooms out, which makes the player effectively "farther" from the avatar.