Here's something worth reading: https://starcitizen.tools/Object_Container_Streaming
I’m sure it was a very important optimisation for Star Citizen, but it’s not like some amazing tech that will be important for the game industry or anything.
Star Citizen had some awful performance problems, and because the development is quite public, optimisations that programmers are working on get important sounding names and publicity all their own. If it wasn’t for that, this would just be an implementation detail in their engine.
As you said, OCS was a needed optimization at the time it was rolled into the publicly facing releases, and I thought it was an interesting topic to at least share with others who are interested in the discussion (the amount of negative downvotes I see now maybe suggests folks don't find it as interesting as I do as someone who merely plays video games but doesn't develop them); at the very least I wasn't aware that it's a common technology, but it is still an interesting technology to me nonetheless.
As fun fact, its something you are getting for free with Unreal Engine 4.smth these days because Epic needed it for Fortnite Battle Royale ;)
The SC version has a star system, which has containers for areas around each planet, which has containers for moons and the planet, and you go down to the planet and it has containers for cities, which have containers for buildings which have containers for apartments. I wouldn't think Fortnite would bother rigging it up that way, but maybe arbitrary nesting is a natural way to handle it.
Of course there's the additional mess of coordinate systems on a spinning planet orbiting around a star that your average shooter doesn't deal with either.
But the really impressive part is that they managed to stuff this into an old version of CryEngine and make it work. They really lucked out with CryTek running out of money to pay their programmers with, which let CIG scoop up a bunch of the engine devs and start their Frankfurt office. When it comes down to it, that might be what makes the whole project possible.