It's nothing more than the Bryce effect: playing with a new toy. People are finally breaking out of the P4 trope. Right now its raytracing and reflections. Next is going to be a lot of HDRI. Then it'll be into the SSS effects, as people figure out how many things actually -have- subsurface scattering. You are finally seeing the same thing with dynamic hair and cloth. Once the 'See what I can Do!' wears off, things will settle back to a more reasonable level across the board.