Flight Sim is doing some pretty impressive things under the hood too. The game includes literally the entire world and their textures are of such high quality that the game actually takes up petabytes of data. They stream in data on the fly using the internet to make sure you get near photorealistic environments at all times. We finally have power of the cloud. BTW, the game has traffic in cities and animals in the wilderness. It also has real world planes populating the skies when playing online.
They are also using a fully dynamic realtime GI system. Everything casts accurate shadows. Every single cloud has their own shadows. Every single light source on the ground during night time illuminates the sky including your own airplane. Every single street light (literally tens of thousands of them) has its own light source. All volumetric.
I dont understand why you are bringing up a lack of NPCs or AI when this game is literally pushing the CPU more than ANY game in the history of gaming. Everything in this game from the weather systems to wind and cloud physics is all realtime and not baked. It's simulating things Ratchet and other traditional games dont even bother baking. Besides, GT Sports doesnt have any particle effects or animations or NPCs, should we also dismiss the game when discussing visuals? What about Driveclub? Arguably the best looking game of last gen with easily the best looking weather effects of all time. By your definition, DC would be instantly disqualified from any discussion.
Bottomline is that Flight Sim is the first true photorealistic game and it is not faking any of it.