So why is it hard to "source" this stuff when I just gave you the links? You obviously have an Internet connection. If you have a credit or debit card you can make a few mouse clicks and have any of this stuff you want at your door in a few days, tomorrow if you're willing to pay for that. Heck, it's often quicker as well as easier for me to buy online than it would be in person even if the stuff was carried by local stores. I'd have to find time to drive there, buy the stuff, and bring it home. Given my life and schedule and Atlanta area traffic it might be a week or more before I could arrange that, whereas I can order from the comfort of home in a few minutes and have Santa bring it in his brown sleigh in a couple of days.
"On the way out?" Of what? In terms of mainstream use for the vast majority of picture takers it isn't "on the way out" but rather already long gone. We all know that. But in terms of being available for hobbyists and artists who prefer to use it, it isn't gone and doesn't seem "on the way out" at all to me, with the exception of E6 and even that might be rescued by Film Ferrania. Color neg is in an odd sort of place between E6 (which I once referred to on here as having "one foot in the grave and the other on a banana peel" so I obviously see your point about E6) and black and white, which seems safe to me in general terms for the foreseeable future. I think color negative film will be around for a while yet but I'm far from certain about it long term. RA4 paper is still made in fairly large amounts because it's still the best quality way to make affordable prints from digital files.
Fortunately for me my main interest is in black and white and I think I'll be able to get all the materials I want, maybe not the same selection but enough to do what I want, for the foreseeable future.