Based on the presented frames, one might think this is a GTA 6 gameplay leak. But in reality, it's still GTA 5, just with the CoreFX mod installed and a set of ReShade filters.
To achieve such a smooth picture, the authors used a top-end PC build with an RTX 5090 video card and a 9800X3D processor.
This work once again shows why mods remain the main advantage of PC gaming. Thanks to enthusiasts, even old projects get a second life without the need to buy official remasters, which often look weaker than fan-made developments.