The text from the Darkness spell specifically says non-magical light cannot illuminate the darkness created by the spell. The spell works more like inky black fog rather than a non-illuminated area. This is why Darkvision cannot see through the area.
No, the spell works like darkness, because it creates darkness. Regular vision can't see through regular darkness, and it can see things not in darkness. Darkvision can't see through Darkness, and it can see things not in Darkness.
Special senses Truesight and Devil’s Sight would only let you see in Darkness not Heavily Obscured of other type.
No, the spell works like darkness, because it creates darkness. Regular vision can't see through regular darkness, and it can see things not in darkness. Darkvision can't see through Darkness, and it can see things not in Darkness.
Tweets aren't rules. If Crawford disagrees with the books, he's wrong. BG3 got it wrong.