Hi, guy that has a modern computer that can run really, REALLY high-end video games here. There's quite a few ways to determine whether this is fake or not, but I'm going to run through just a few of them.
1) Shadows: It's the Year of Our Lord 2023 and computers still have a time and a half trying to render shadows. Sure they're good at rendering big shadows like, say, the silhouette of a tank, but the closer you zoom in the more lines you'll start to see. DRG, that image you posted shows some insanely good shadows. If this was a game like Warthunder at that close a zoom you'd start to see little jagged lines where the shadows are rendering at a lower quality
2) Smoke: Smoke simulation is fun, so much fun in fact that people will spend time and money to not have to deal with it! When smoke is rendered it tends to appears as a sort of texture that expands to fill out a screen. It'll clip through ground and phase out of reality and all sorts of excitingly boring stuff. In the footage shown it.. Doesn't do that. At 0:13 that smoke reacts extremely rapidly, something modern computers aren't really good at
3) Trees: Trees? Trees. Most modern video game trees look horrible up close. They tend to be little tree-like greebles stuck onto a solid object to make it look authentic from far away. The trees at the start of the video? Nope, those are real.
Here's a link showing off some of WarThunder's newest graphics back in 2002.
Additionally
Here is a picture of War Thunder's Leopard 2A6 model.
The detail is excellent, but it's missing all of the 'clutter' on the tank in the video. Namely the twigs stuck in the small spaces and a few of the bolts on top of the turret -- things a game would have a real tough time replicating.
Sorry for the derailment here, just figured that with all this talk of modern graphics and AI it's important to recognize what's in a game and what isn't. As it stands? This looks nearly 100% authentic to me, unless someone took time and energy to create an incredibly detailed render of the Leopard 2A6 and design a pixar-quality video around it.