It's not either / or. A given artist can get better results with less manual effort with path tracing. That's the main reason almost all offline rendering has moved to path tracing despite it being much more computationally intensive. Artist time is more valuable to them than CPU time.

Pixar thinks its artists have better ways to spend their time than placing lots of fake bounce lights to approximate true GI. It's not that they couldn't get some very good results given enough time and effort, it's that they can get better results leaving that stuff to the renderer and using their time elsewhere.