It's unfathomable to me that the one method of image capture in all the history of man is discontinued. By all rights, all other kinds of film would have died out with only Kodachrome remaining.
The "one kind?" Did you perhaps leave out a word? Something like "permanent" or the meaningless "archival?"
I have a large collection of Kodachrome transparencies that I exposed over many decades, mostly 35mm, but quite a few 120 too. All are in excellent condition, and will almost certainly remain so for the rest of my life. However, every one of them are on cellulose acetate base, which will, eventually, become "vinegary" and then disappear. No one should deceive themselves. Any images worthy of long-term preservation are best kept in digital form, and made part of a maintenance program that includes regular backup/copying as well as format conversion when technology evolves over time. I miss and love Kodachrome, but am not so naive as to think it could outlive properly cared for digital data.