No simulation is perfect, and in the case of space "sims", there's always some necessary extrapolation and a measure of suspension of disbelief required. But in the case of ED, there's way too much compromise on the gaming side to call it a sim. Things like maximum speed, gimped yaw rotational thrusters, supercruise plane vs instanced space bubbles you get teleported into, magic light-speed communication working for criminal bounties but not for trading commodity prices, pink nebulas... It takes me longer to deliver yoghurts from Paris to Stuttgart in Euro Truck than to ship food cartridges across several light-years. Frontier felt way more of a simulation in that regards, with time really flying by as you trekked across the galaxy, civilisation felt like remote islands in the empty. Of course, multiplayer gets in the way for this to happen in ED.
Then there's the unfinished nature of it, meaning that planetary landings aren't there yet either. So the sim experience is that bit more limited, and also happens to feel a bit lacklustre in terms of 'fluff': docking/takeoff is very barebones in terms of procedure and interaction compared to, say, the modern aircraft/airport equivalent. Heck, even starting the ship is a single click on 'launch', after the first checklist had me hoping that some engine starting sequence would be available. Cargo loading/unloading happens by magic over a split second, when maybe it should take a bit of time and/or require you to head to specific (scoop-based?) loading docks where containers would have been prepared after you passed your orders ahead of time while approaching the station.
It's still enjoyable to drift around stations without FA, and well, the game is what it is, with its own charm, but there's so much more to be made on the space sim front, somewhere between Frontier and Orbiter...