Hmmm... while there has been a lot of Biden+12 in WI, most of the recent PA polls have been this close or closer. I always thought Biden would have an easier time in PA though.
WI is a bit more elastic than PA, and I feel like the "Scranton Joe" effect is a bit overstated. He was born in Scranton but he's been a Delaware politician all his life.
PA is pretty inelastic though. Just look at 2018. Depends on turnout too, but there is a lot of areas that can swing back and forth (Erie, Lackawanna). Depending on the candidate, they can either be close, or like D+15-20.