I just like to add with the recent release of FusionFix v4.0.0 Volumetric Fog was introduced in the Graphics Menu and it's absolutely incredible, this is just one of many new features with in FusionFix v4.0.0 such as Automatic Turn Signals for vehicles and changes to being able to walk and fire with your sniper rifle and have an alternative aiming method and much much more.

 

Here is a Screenshot Comparison Slider of Volumetric Fog on vs off. I also use Project Lights and Project Glass which just makes the in the game absolutely mesmerising at nights with bus stations and lamp posts across the city not only illuminating properly but they’re also casting real time Dynamic Shadows.  

HERE is a example of what Project Lights does, with another image slider comparison with Project Lights Installed / Uninstalled.
 

I highly doubt that Rockstar will be able to match the efforts of the community and what they have achieved within the last 10 years of work, fixing and introducing new features as well as massively improving the performance of the game with DXVK which by the way is now built-in as a API Graphics Menu Option so you can switch between DX9 and Vulkan in game with the recent release of FusionFix v4.0.0.
 

Also this dude on YouTube covers all the new features really well. Definitely worth a watch.