I can buy the first paragraph, but the Matrix demo is only 25GB on my PS5 and contains a full next gen open world city. Even if they added fully modeled indoor segments that take up 3x more space, we are still looking a 100 GB game on par with last gen games like RDR2 and Horizon.
Matrix Awakens is
29.07 GB on Xbox. So give or take a GB on whichever platform it is compiled for.
But also, "only 25GB"... only? It's a relatively modest city area made with heavy usage of procedural generation and replicated assets, with few audio samples or other multimedia included much less all the other materials that go into a game. There are apparently just
44 unique buildings populating the entire
City Sample (aka the open-world section of Matrix Awakens,) which can be used to make a nice-looking city when spread around and stylized but isn't going to be enough to create distinct boroughs or open parks or landmark skylines in say a realistic NYC-set game. (Although they do augment building with different decoration and even rough shape shifts as well as other visual cues to make them distinct.) Those square buildings and the highway system are most of that "full next gen open world city"; then they randomize in some people (which mix&match from 12 heads, 6 bodies, and various bits of wardrobe and fabric textures) and place some props, and that's the city. And that's
90GB of assets, which compiles/compresses down to an executeable of 25-30GB* in a PlayStation or Xbox game build.
(**EDIT - Big adjustment here, the PC version of City Sample (which has the same map as Matrix Awakens but does not contain any of the video files or the opening action sequence) is a more economical 18.14GB. So, we're fitting more in per GB than my original FUD indicates, but we also needed almost 11GB for, what, 3 minutes of gameplay?)
So, you could make a game of that 30GB. They did make a game of it, sort of. (Matrix Awakens doesn't have "a point" to it, but you can drive around and crash and jump and discover stuff.) But if you were going to make a real game on a AAA scale, you're going to need significantly more, and you will ultimately need to be thrifty with your assets because you need to deliver something on a disc, or at least you need to be concerned that tipping over 200GB installed on drive is a big ask of gamers. If developers can stay in that 100GB range then okay, it is the standard for now, but I disagree on your math that they'd only need 3X this demo's content in order to make for example a full-scale Matrix AAA game.
We'll see when more UE5 projects are actually compiled for release (and especially now that it's beyond Early Access and developers can produce finalized, releasable content with it,) but asset size will be a concern.
The Market of Light, a UE5 project made available to the public, is a tiny bit of gameplay area and yet that's I think 2.5GB in its little corner of the world.
Either way, though, I don't really think that's why Coalition's newest demo is not impressing you, it just is what it is: a short little demo made to exercise the feature set of the engine and production methods of the team. It would have been nice if this was finished back in June of 2021 so that their Alpha Point demo would have made more sense, but ever all of their demos put together still don't add up to the quality or depth of content found in the very first UE5 demo, Lumen in the Land of Nanite, way back in May of 2020. (Also I agree that, in 2022, showing this when so much stunning work has been done by amateurs in UE5 Early Access is not ideal, whether it looks good or "too cross-gen" to viewers.) But the point isn't to blow gamers away, it's to exercise the team and provide some feedback for MS's teams and get an idea of the work process/challenge as they go into their actual next project.
