How do you explain that magazines and millions of publications around the world strongly preferred receiving transparencies for their pagework, not negatives? For many decades transparencies were the print reproduction standard in publications (newspapers stuck with B&W for its speed in D&P, but colour work for inserts/spreads and magazines were largely colour). Negatives would often be rejected simply because editors wanted the immediacy of assessing an image on the lightbox in its real form, without having to fiddle a negative on a scanner. National Geographic is a very good, long-standing example of the application of slides to print. That we are still printing from slides today is not much different, but certainly much more efficient, straightforward and fuss-free than Ilfochrome -- which is why so many of us don't want to see it come back!
Also, printing from this medium slides) points to effective and proven multiple use that has been going on for at least 60 years, not that many amateurs were/are aware of it or its extent (as outlined above!).