I'm curious, as I'm not in the games industry: what type of model does one typically see? I actually expected it to be something along those lines.
I did read a bit on that, and tried to implement a simple game on it. What I've learned is:
a) it seems to be vapourware; there are some blog posts about it and examples floating around, but that's pretty much it
b) it seems to make sense only for MMO games, which are glorified interfaces to database tables anyway - hence the ECS model, which is about treating your game design as a database problem - fits it well
c) experienced people I talked about think this is a stupid approach, for reasons I'm probably too dumb to understand (except the efficiency ones)
d) in games that are not database-like MMOs, it's getting very hard to figure out what should be a component or a system, how many systems should you have, etc. etd.
e) it seems to seriously complicate implementing game logic - you end up spreading code that belongs together across many different "systems"
It is true that there are some degrees of limitations and implementations that different game engines go through and none of them is a 100% pure CES engine (something like http://www.chris-granger.com/2012/12/11/anatomy-of-a-knockou... ), where all systems are separated from the components and the entities containing them. Usually you'd have sets of components and systems and whatnot and different hierarchies, but the gist of it is still a Component-driven system.
One thing I vividly remember from learning about ECS is that the main sources on it repeatedly remind you that what UE or Unity do is not ECS, and that the way they understand the concept of "Entity" and "Component" is different. Entity Component System is not what UE or Unity do.
Using an ECS for game design actually has enormous advantages when you are coding a high-performance game in a language like C or C++: you can lay out the components of the entities however you want, so that systems on the hot path have access to as many components as they'll need without blowing the data cache. I'm not actually doing that for this game, but still, it has advantages outside of just MMOs.
[0] https://nullawesome.tumblr.com, https://github.com/bitwize/nullawesome