Yes I agree, the game doesn't need pure fantasy stuff. No Man's Sky is already out there for this, and on the 14th of August it will also receive VR support.I'll get on board with your sentiment that the game could use more fiction. But I'm not going to say it 'needs' it, that's an opinion. While I definitely lean toward agreeing with you, I'm not sure pure fantasy is what attracts people to this game. Look at black mirror, the horror lies in how few degrees of separation lie between the episode and real life. I feel this game is pushing to utilize the same draw, albeit not for horror. This could very well be an extremely realistic representation of 1200 years from now, where theoretical or fantasy physics aren't entertained and it's just an actual possible future. For instance; the frame shift drive is based on technology that NASA has already expressed interest in developing and thinks is viable with exotic material (Alcubierre drive). And while scientists hypothesize these diamond planets may exist, Starforge has only ever been shown to produce procedural generation that resembles real discoveries supported by existing data (though I suppose you could throw green gas giants in my face by that argument). In summation, I believe the draw for most people is that this is the closest to exploring the actual milky way galaxy that we'll will ever actually get in our lifetimes.
I believe ED needs more realistic features for planetary gameplay like Vulcanoes, Magma rivers with valuable and rare materials difficult to be gathered (with a brand new SRV dedicated for this type of mining), Earthquakes, falling asteroids, caves, more type of exotic life that can live without atmosphere and so on...
The planetary scanning gameplay could also be improved furthermore by adding new scanners to the SRV to scan particular surface fissure on the planet surface. There's a lot that can be added in this respect.