My PBR Texture looks better in Viewport than in the Render i'm rendering an Image of Bane's Mask in Blender. Its on a wet road, which looks high-res in viewport.
This road looks very flat and dry after rendering in Cycles.
Viewport result:

Render result:
This is because the material preview render in the viewport automatically uses an environment texture from “C:/Program Files/Blender Foundation/Blender/2.91/datafiles/studiolights/world” as the world background, but by default the rendered world background is solid grey. You can load one of these backgrounds and pipe it into the world’s background color with an Environment Texture node.