I'm less sure that the 21st Century market economics are as simple as they are sometimes described, although I tend to broadly agree that product will cease to be made if too few people buy it.

Only slightly tangentially, where is all the TSF and Xray film being coated? If in the same plants as the mainstream photographic films, then to some minor extent that may also support photo film (in the sense that it will contribute to volume production that makes the plants viable; the flaw in this argument is rather obvious, of course, but there might be a grain of truth)