The challenge is generally in making enough of the pre-cursors in enough quantity to make it cost effective.
So early technology, like charcoal :-), easy to make the pre-cursors. And for some silver halide films that is still true (19th century tech). But as you get to things that got their start in the 20th century and required a bunch of composite things to be in place in order to exist, those things may end up outside of the range of manufacturability (at a market making price).
It will be interesting to see the things that fall out from that.
So early technology, like charcoal :-), easy to make the pre-cursors. And for some silver halide films that is still true (19th century tech). But as you get to things that got their start in the 20th century and required a bunch of composite things to be in place in order to exist, those things may end up outside of the range of manufacturability (at a market making price).
It will be interesting to see the things that fall out from that.