Consider all of the issues:
* A toxic chemical process for development. Both the source negative and the (thousands of) projected copies.
* Weave, both during filming and projection.
* Aspect ratio madness because of legacy formats. For example, academy formats have an offset center thanks to the audio track.
* Light leak, and other physical film issues you don't have with digital.
* Film is very inconsistent, and between projects, stock choices can make the source material really bad to work with. Take the legendarily bad Vision 500T that many cameramen would use even on critical bluescreen/greenscreen shots it had no place in.
* For IMAX, going digital has the added benefit of losing weight. IMAX reels can only go about 90 seconds at a time. That'll also help high speed. Filming 500-1000 fps will tear through a 35mm reel in about 5 seconds. Again, pretty wasteful when you think about it compared to using a Phantom.
Now it's just a matter of getting all theaters to use digital projection.