Its based upon the galaxy, but its not a realistic simulation of the galaxy. The ships have always been based upon 'planes in space' - which is obviously non-scientific, the sound design is great, but again not realistic, again and again, Elite: Dangerous is a mix of realism and arcade and has always been.
This is a consistent argument rammed up against FDev, and I sympathise but...
1) a REAL LIFE physic accurate space game probably wouldn't be a FUN game
2) a games soundscape can really make or break a game - a totally silent game would not be much fun. You could of course run the soundscape as your ships internal audio but... I'm not os worried that real ships don't make those noises...etc.etc.
3) D Braben has always maintained that the Galaxy simulator is as 'real' as they can make it - but I don't think they are attempting to maintain tat 100% of things in ED are 'realistic' - how could they?
4) I suppose another consideration might be - in the 1950's very few people imagined such possibilities as WIFI, mobile phablets, CT Scanners etc. Arguing that 'this' or 'that' isn't real for the year 3303, is a bit salty.
5) Last point, I think perhaps definitions of 'arcade' are fluid. I see an arcade game as something with flashing lights and booming noises that can be picked up and put down and is a pew-pew blast fest over in a few minutes / hour at maximum. ED is intended to be a MASSIVE experience/. I think the proposed game time for Witcher is 180 hours, and elite is supposed to be 'endless' so the features contained are meant to take time, meant to take the player through a galaxy of developments and experiences as they get to know how the ED Universe exists and the interactions within it. Consequently it should NOT be arcadish in any way. But yes, adding arcade type features (Looking at you CQC), seems to be a nod to a more A.D.D. crowd incapable of setting and managing their own long term goals and expectations who want a 20 hour gameplay experience not a 2000 hour gameplay experience. I just think the short-term arcade gamers enticed to look at ED are often, HUGELY dissapointed - but then so they should be, they just got in the wrong game. Engineers is not in my opinion an arcade feature and neither is Powerplay - they are just contentious in their application.