Sans’ jokes are the equivalent of those “joke books” you’d read in 5th grade. They’re so clean as to be incredibly lame and there isn’t one edgy or dark thing about them. The fact that they’re lame and groan-worthy and just plain terrible is the POINT.
Papyrus on the other hand…. I… I don’t know if he MEANS to make dark jokes or not… I think he just… says things??? and they unintentionally end up being hilarious but also kinda troubling???