My first experience with sensitized products going bye-bye was listening to the older guys moaning about DuPont dropping their favorite high speed film, Superior 4 in cassettes back about 1960. They hung in there with sheet films and papers. About 1968 they introduced Varilour which I believe was the first paper to utilize brighteners in the emulsion for cleaner whites, and they'd already mastered the art of intense blacks. DuPont was the company that first came out with a variable contrast paper, Varigam.
Before 1970 arrived DuPont was out of the sensitzed products business. No film, paper, or chemicals.
Ansco hung in there, changing its name to GAF (jee-aye-eff) and introducing the best medium speed film I'd ever used, Versapan. They produced a number of heavier-than-double-weight portrait papers that were very popular. Soon enough GAF was out of the sensitized products and chemical business.
But there was no shortage of film or paper on dealers' shelves. Luminos entered the market with decent B&W paper at half the price of Kodak. "Off-brand" B&W film was available from Supreme and others.
A few years ago Kodak introduced T-Max tabular grain B&W films while Ilford introduced their Delta films, and NEITHER company dropped their conventional films. And Fuji entered the market in a big way! Fuji and Kodak have been going head to head to try and dominate both the amateur and pro markets with ever broader line-ups, offering choices of contrast and color saturation in a multiple of ISO speeds.
Why would they be investing so much in a dead technology? Because film ain't dead.