Slide film in general, and films like Kodachrome in particular, have been the proverbial canary in the coal mine for the last few decades. It's a tiny niche of the film market, and almost always has been. I've long marveled at how many different transparency films there were on offer for so long.
I still contend the the advent of digital film scanning started the decline for slides, which might sound funny, since for me, the film scanner was my entreé to finally being able to properly print from my slides without the rigmarole of, say, printing Ciba/Ilfochrome in a makeshift darkroom. However, this development also put negative film on equal footing, and the siren song of more-controllable dynamic range was too strong to resist: up to about 1999 (a year after getting my first film scanner, a used Nikon LS-10), about 70% of my shooting was still with slide film; it quickly fell to about 5-10%.
Between Kodak BW400NC on the b/w end, and Ektar, various flavors of Portra, and the occasional roll of Gold 200 for color, C41 is covering most of the bases for me. High quality, easy access for both purchase and processing, and also reasonably priced on both counts. That's a lot to like these days.
Besides, I have such a huge archive of slides yet to be properly edited, it's not as if my slide projector will be out of a job anytime soon.
- Barrett