Went from being the next Spielberg to some kind of mainstream von Trier
In that with his last two movies, The Visit and Split, he's basically making intense, disturbing, thematically unpleasant movies that aim to provoke an extreme reaction from his audience. Movies that have more in common with the recent von Trier works, such as Antichrist or Nymphomaniac, but aimed at a mainstream film market.
It's hard to reconcile the notion of someone once competing with movies like E.T. and Jurassic Park who now shoots scenes of a kid having a soiled adult diaper smeared in his face (The Visit) or a movie where the theme is purification through physical suffering and abuse (Split).