Sure but like... this is not trying to be a full AAA open world game, which would require a much larger team and a much larger amount of time. It is trying to show that you could make a AAA open world in Unreal Engine 5. I don't really think they ever pitched it as anything other than a tech demo so I must admit I'm puzzled by all the comparisons of the form "but it doesn't have all these features that a full AAA game does".
The pivot to foliage is also a little weird to me. Sure foliage is another problem in and of itself, but obviously you could have 'regular game amounts of foliage' in UE5 because you can already have that in UE4. But there's not a lot of foliage in the Matrix movies either... When they release the assets feel free to just go drop some of your own in the scene, but I'm not sure why anyone would expect typical game foliage would be a particular problem. Certainly dense forests is something that would be great to handle even better in the future, but you can't do everything in every demo, nor would you really even want to I think.
Whether or not you personally care about fully dynamic lighting on an open-world-sized scene with extremely high levels of detail and minimal pop-in, I assume most people can admit this is something that a lot of people - and specifically developers - *do* care about. Obviously I'm biased, but that to me is the main achievement of this demo; the rest of it is proof of concept level stuff to convince folks that none of this is being faked.