I agree with most of what you say, but
ED also runs very well on my PS4 Slim. So do many very graphically-demanding games like Uncharted, HZD, GTA, etc. I'm fairly certain Frontier's new dinosaur game will also be made available for consoles, so I'm not just not buying that atmo planets are out of the reach of current hardware, especially with the guy who brought 3D graphics to 1980s 8-bit computers leading the charge.
I disagree with the "at all", as I've encountered worlds in NMS that look very realistic, more realistic than the parks in ED's agricultural and "Disney World" stations. I'm sure this has to do with the NMS's RNG seed giving some planets just the right kind of foliage, color, lighting, terrain, etc. Point being, take NMS's engine and narrow down the parameters in to strip away the 'fantasy' aspects, and you'd get worlds that would come pretty close to 'fitting in' to ED's motif. And who's to say that plants don't use purple chlorophyl when lit by a blue/violet sun?