As of right now, the Fog properties within Lighting does not affect player visibility range. Even if the FogStart and FogEnd properties are set to 0, you can still see objects that are hundreds of studs away. Right now, Lighting fog does not affect visibility whatsoever - instead, it simply changes the colors of objects.
Being able to implement visibility properties to fog within Roblox would make fog seem more realistic.
This is what fog SHOULD look like:
This is what Roblox fog looks like:
In the example above, you can see objects hundreds of studs away clearly ^ in 100% fog
edit:
As a possible solution, fog should also affect the skybox, as the skybox is completely independent of Lighting fog… The current implementation of fog is “alright” for workspace instances, it’s just that the skybox appearance should also be affected - fog (in real life) is in the sky so it makes sense that the skybox should also be affected.