Entity Component Systems notes from someone who doesn't write games and didn't know what ECS was.
- State shape is more explicit, so much more likely to make good sense as an app grows
- ECS encourages much less plumbing for data flow between parts of an app, since systems can just read whatever they want.
- For big stateful apps, OO seems to encourage an 8-to-1 ratio of data plumbing compared to biz logic
- easier to safely share behavior
- Supports state serialization for record/replay debugging