I never got around to watching Dark, thinking it was a bit too shallow and not living up to my standards of good dark, but after your post on here I'm thinking of giving it a go sometime.
Stranger Things imo always had the right amount of layers, which I thought many times was nicely balanced with its 80s sentimentality and cheese. I'm somewhat surprised to read that Dark is darker, more eerie than ST and has more complex plot lines.