Just a quick comment about Kodachrome, if I may.
It's probably the most stable of colour emulsions because, simplistically, the dyes are not in the manufactured film but are introduced during processing in a technique not a million miles from Technicolor so can be more stable than photographic dyes. Certainly the colour in my my Kodachrome slides has fared much better than Ektachome taken at the same time, but Ektachrome had the benefit of several emulsions of considerably higher speed than Kodachrome. Kodachrome can scan very well but is a relatively high contrast film so may need some measure of contrast control applied either during the scan or in some sort of post-processing - it's one of the reasons it never duplicated very well.
As for fungal attack, in high temperature, humid conditions every film emulsion is an ideal breeding ground for fungus, after all gelatin is an ideal medium for growing bacteria. I can assure you that Kodachrome is not especially susceptible but, as with all things, two films stored close together may well demonstrate different storage characteristics.
Most of my photos were taken on Kodacolor negative film because I preferred prints and reversal films were never great for printing. Some of those strips of negative have suffered deterioration, though, both from dye fade and fungal attack when the negative album in which they were stored became damp during an accident with a dehumidifier which overflowed under the bookcase in which they were stored.
Interestingly (or perhaps not) there are still quite a few photographers, both amateur and professional who prefer to use film. There's a story (which JimG may be able to confirm) told by the Head of Film at Ealing BBC Studios about a plan, soon after the introduction of tape rather than film recording to send all the crews out over Christmas to record what people who were working were doing on Christmas day. Tape was so inexpensive that crews shot miles of the stuff and the result was so cumbersome that it was found to be impossible to edit. Film, because of its expense, pretty well automatically imposes some sort of discipline.
True movies are also still made, although in volume terms certainly many fewer than even 15 years ago. As an example Christopher Nolan prefers his movies to be shot on film for the discipline and "look".
Brian