No. People act like Peterson has regressed. All he's done is improve his receiving and blocking. The reason he's not having huge monster games is because they don't need him to and if you don't need him to why pound him 25-30 times a game? Pro long his career by keeping him fresh when you have a HOF Pro Bowl QB next to him to rely on.
Yep. Peterson has many more weapons around him than he's had in recent years, so his numbers are automatically going to decrease as a result of it. He doesn't have to carry as big a load. People need to quit comparing players based on stats and take time to actually watch a game or two.