I enjoyed your analysis regarding digital photography and computational power. However, digital cameras are facing real limitations. The desire to build better sensors with faster processors and concomitant data transfer speed and storage is one limitation (the same limits that are facing all computers today). Moore's law is breaking down. Camera makers are are seeing these limits already. The power requirements to keep the processors running are a real limit.Yet, the potentials, given that the digital medium is based upon computer technology are, compared to silver and gelatin, limitless
Lens and sensor densities (number of megapixels) provides another real limit. A limit camera manufactures are basically at right now. Their only option is to increase image size, but this would lead to heavy cameras. It is predicted that cameras will scale to the third power as image size increases.
I guess faster processors can lead to pixel shifting and also better image stabilization. This is fine for slow moving targets, but it won't help in photographing sports and perhaps wildlife.
A minor flaw in you analysis is that you are comparing modern cameras to a static technology (film). Newer, better performing films were still coming out at the time of digital ascendency. However, there was no market to release even newer chemistries, let alone continue with film RD. A what if game for sure, but it would be exciting to see today's film offerings if the film market remained. I'm sure the film giants could have still made astonishingly big gains in the intervening 20 years.
Here is a nice article discussing limits in digital cameras.
http://www.northlight-images.co.uk/physical-limits-in-digital-photography-2/