Looking back, there was NOT tremendous evolution in B&W film emulsions from the 1960s to the 1990s...Tmax emulsions were launched, but many photographers preferred trusty Tri-X over the new stuff!
In color film, there was more evolution than in B&W...first, faster emulsions with ASA 400, then finer grain in the ISO 400 films being very similar to ISO 100 emulsions!
So where would we be today in films, if digital had not bouldered over the film world?!...I don't think a whole lot different that what we have today...simply more varieties of emulsions, rather than emulsions dying off like soldiers on Civil War battlegrounds!
Not many emulsions have been killed off recently (any?) without getting replaced with something similar or better soon after.
There was some intriguing and sometimes exciting ideas, that got taken out of the mothballs too late just before digigeddon, when the film manufactures really started feeling the dragon breathing down their neck and their projections didn't fit and/or their own digital arms suddenly revealed themselves to the public at large, to be as halfhearted as they had always been.
Analog Photography had the Silver barrier. Since 1850 to 2000 insane amounts in R+D had been invested yet, with diminishing returns, but industry was still using the same than Archer and Le Gray 150 years before: Silver halide crystals ...so a revolutionary improvement in performance would have been dificult. Perhaps a bit less grain for the speed, a bit more DR, and for sure a more eco friendly manufacturing/processing.
There is no inherent barrier in using the same basic material for a long time.
An analogy could be mild steel or silicon. Mild steel has been used extensively also since the 1850s, but is used in new ways still with incremental tweaks and, sometimes revolutionary improvements that make the basic material stronger, less brittle or less prone to corrosion.
Same with sillicon and silicon dioxide/silica. It's used extensively for concrete and windowpanes and have been for thousands of years. Yet there is still significant improvements made to the mixtures and composites for various uses.
Silicon is of course also use as the substrate for integrated circuits and has been for sixty years.
It's unfortunately very common to have huge amounts of token RnD resources put in by a company to a research center, only to never have the results of said research used, because it doesn't fit in with the current "paradigm" or sales infrastructure.
A commonly sited example is Xerox PARC, where all the technology you are using right now was if not invented, then made into a practical and useable form in the seventies (plus more and often better, but that's another far longer story). Xerox did nothing with it apart from commercialising the laser printer, and putting out an insanely priced workstation in the early 80s.
Other examples are Bell Labs, IBM and Microsoft research.
Similarly there was a tonne of film research at Kodak, Fuji and Agfa done through the years, that could have been put into products with a bit more corporate muscle behind it.
It's possible to get silver halide film up to ISO 24000 with acceptable results. That has been demonstrated numerous times. The problem of keep ability could have been solved in a number of ways.
For example:
https://books.google.dk/books?id=kkPBDwAAQBAJ&pg=PT50&lpg=PT50&dq=iso+24000+film&source=bl&ots=m62L9pbEoF&sig=ACfU3U1PsnZJh_053pyRug5CfEgj2TX7Nw&hl=da&sa=X&ved=2ahUKEwjMma6t1rTmAhWKLMAKHR-QCxUQ6AEwA3oECAoQAQ#v=onepage&q=iso 24000 film&f=false
Good Enough is often deemed as "what is possible" until someone comes along and shows otherwise with force and money behind them, or changes the rules completely as happened with photography.
I believe it self-evident to anyone well versed in the art, that film is the vastly technically superior image recording medium/method.
Its quantum efficiency, while not unimportant and is something that would be nice to have addressed, is a matter that can be overcome with a bit of ingenuity from the enthusiast.
Bounced flash and radio controlled flash, for starters is readily available, will produce beautiful results and is not a compromise at all, as some seem to think.
Controlling light has always been part of the art.
