So PBR has become the default in the industry since starting around 2009 but really took off around 2013 - 2014. It was adopted because it could represent a larger range of physical surfaces then previous models while looking more consistent and being easier to understand [0]. Before then most 3d games either used Phong or Blinn-Phong [1] but they were hard to control for artists and they didn't really represent many materials very well.
> So PBR has become the default in the industry since starting around 2009 but really took off around 2013 - 2014
I think Disney's publication of their Wreck-it-Ralph movie + papers, showcasing that a singular shader created all the different characters of that one film, really took PBR to the mainstream.
A highly popular movie that showcased the methodology, as well as published papers on the subject to scientific journals really hammered the point home. This was a new paradigm shift and far easier to think about than earlier models.
> We deployed our “Principled Layers” shader on Wreck-It Ralph and used it on virtually every material
except for hair (which still uses the model developed for Tangled).
A statement like this from Disney is truly a mic-drop moment. Especially given how impressively diverse the characters were from Wreck-It-Ralph.
Wreck-It-Ralph was 2012. So pretty close to your timeline. (Especially if we consider that it takes time for people to see the movie, read the papers, think about the situation and realize that a paradigm shift just happened).
[0] https://marmoset.co/posts/physically-based-rendering-and-you...
[1] https://en.wikipedia.org/wiki/Blinn%E2%80%93Phong_reflection...