Ron's comment about 1988 is apt, by then Fuji's 50D (and 100D) had really begun to eat into the Kodachrome market.
The advantages were films which could be processed quickly, with superb colour rendition, tonality and sharpness. Unlike the US, which had a number of processing labs, in Europe Kodachrome processing was slow and most photographers needed the film processed within 24hrs.
The other advantage of the new Fuji films was they were available in all formats.
Since the release of 50D and 100D I've only used Fuji films E^ or C41 for my colour work.
Having said that Kodachrome 25 slides do have that unique edge. If only the'd make LF Kodachrome again . . . I seem to remember seeing some by Weston or Adams at an exhibition a few years ago.