I made some small and easy updates. I tested alot and wrote alot and deleted most things. Gemin had the Fog Idea :)

First Change:
I changed the gbuffers_skybasic.fsh color grading for the sky. It makes the sky way more light blue isntead of the dark blue I had before (image included)

baseSky.r *= 0.1;
baseSky.g *= 0.65;
baseSky.b *= 1.8;

Second Change:
I added Exposure to the final.fsh. One Problem was that it got so bright, that lighter texutres like sand looked basically white. So i went in the composite.fsh and multiplied the lighting by 0.85 so it will get darker and compensates the Exposure (image included before and after):

final.fsh:
float exposure = 1.3;color.rgb *= exposure;

composite.fsh:
vec3 finalColor = albedo.rgb * lighting * 0.85;

Third Change:
I added a fog near the render distance. It was Geminis Idea to add fog. It was only 2 lines to add:

float fog = smoothstep(far * 0.7, far, length(viewPos.xyz));finalColor = mix(finalColor, fogColor, fog);