Has he honed them, or is he succumbing to the simplification of music and lyrics in the 21st century? I'm not saying you're wrong, or I'm right, just an alternate way of looking at it. I sometimes wonder if the problem with all long term artists, is that they simply aren't hungry for "it" once they reach a certain level of comfort and fame.
Or they're just extraordinarily filled with talent and curiosity, like Jonny Greenwood.