> Sam Raimi is a very accomplished director so you don't notice this unless you look, but the CGI buildings in the movie are actually _much worse_ than the ones in the recent PS4 game. It highlights the adage that there's no such thing as bad CGI, just bad filmmaking.
I think the better question to ask is: What CGI effects from 20 years ago can't be achieved in real time today?
Finding Nemo was almost 20 years ago and as I recall, Pixar did a lot of work to reproduce the look of marine animals that have translucent layers to their skin. Seems like a level of detail that real-time engines might not bother with.
But yeah, the Mandalorian used real-time rendering in-camera for a ton of its scenes. They fudged it a bit by using wide apertures so the backgrounds were a bit soft, but it obviously worked very well.
Human skin is translucent too. Real time Sub-surface scattering has existed for years and is now to making it into games. There's an excellent writeup here:
I think the better question to ask is: What CGI effects from 20 years ago can't be achieved in real time today?