Should a creature with Devil's Sight see in a fog cloud?

[DontOpenDeadInside]

I'm not talking about the current bugs that allows to see inside all clouds but fog cloud is not darkness so should Devil's sight function with it or not? I'm asking this in the sense to figure out of strong the Devil's sight is within the rules of 5e. When entering darkness cloud you get the message "immune to blindness" if you have Devil's sight but that's just the case with the darkness cloud isn't it?
What I'm also trying to figure out is if it will ever be possible to cast both the Fog cloud and Darkness cloud next to each other to allow a Warlock to increase its "safe space"

[Hans]

Fog is not darkness. You said it in your post. In 5E, that is how it works. You can see through darkness. That's it.

[RealDealBreaker]

Think of it this way, it may be dark at night and turning on your high beams helps you see better, but in really smoky or heavy snow conditions turning on your high beams only helps you see the smoke/snow more. The smoke/snow/fog is a physical obstruction to vision, not merely a reduction in light.