I’m 100% sure we get more data than what is rendered in the sim. For example the ambient visibility on weather debug tool shows varied visibility data that comes from another source than the METAR but it’s not rendered in the sim.
Check that value while you are flying and you notice it changes depending on where the aircraft is located.
METAR haze/fog is always rendered but outside those areas we always get unlimited visibility rendered in the sim. I hope they make that other visibility source rendered in the sim in the future too.
But i agree with @CharlieFox00 that the light from the sun needs to be reflected more. Maybe raytracing fixes that?