Because I think it depends very much on how you look at it.
All well and good, but where is that in Elite? After six years, where is their attempt at realising this ambition? As of right now, I can land on various different biomes on NMS, and walk around, discover a wide variety of plants and animals, explore caves, oceans, feed & ride animals, permanently affect the environment & create bases. Then drive or swim around in various exocraft.
Maybe they are "small", but they don't
feel small. I am small. Planets are big.
Yup.
They could certainly do with more biomes (you can get mods that add 1000s more), but to say they all look alike is simply wrong. You clearly haven't been to that many planets. By comparison, landable E: D planets all look and behave alike. Whatever Stellar Forge may or may not be able to do, it's not currently providing any variety on landable planets. They were even all completely beige for 2+ years.
The main "game" benefit of building a base in NMS is for farming resources. Beyond that, it's just something you can do that can be as creative as you like, and you can share those creations with others if you choose. Others can visit. If you don't want to make a base - then don't. It's not compulsory. There's a lot more to the game than that.
Oh, and there's definitely danger in NMS (if that's what you want) in Permadeath mode.
You want mystery? Well, who actually are you? Why are you there, and why do you not remember a 'before'? Who is the Atlas & what is its purpose? What are the Gek and Korvax all about? What is the anomaly, and where does it actually exist? Just a few things to get you started...
E: D doesn't have bases at all... you cannot affect the environment or game world in the slightest. I can create a cave in NMS, and come back in 6 months, and it'll still be there. E: D doesn't even
have caves.
Sorry, but there's really no comparison. E: D has a heck of a lot of catching up to do, because they dropped the ball big time by not focusing on planetary gameplay after 2.0 and instead faffed around with other stuff that nobody asked for or wanted. All well documented at this point, and no point in re-hashing it.
But looking at the two games side by side at this point, and NMS wins hands down on every level bar space flight.