You seem to forget that the camera flyby travelled for several hundred kilometers after going into the atmosphere. And it did it at high speed, at a high framerate, with almost unnoticeable popping (trees being the exception) and a high graphic quality (at least the sections the camera flew through). Now compare that with other games with planetary engines running realtime: They all have either high framerate drops, or very noticeable popping, or low quality, or multiple of this issues at the same time.
What? No they do not have any issues like that? Terrain in ED Horizons v1 is much more complex than the Perlin Noise in SC planetary tech v2 (yeah no shiny bloom, sry) and runs on a 5 year old laptop with 50 fps in 1080p. What you say is ridiculous. SC is awfully optimised, and it is nothing special for nowadays standards (and is still years away from release).