Just to point out, pre-digital era film was being consumed not by photographers but really by people taking snapshots on point and shoots and disposables. Fill will never be in every home again and that's not the goal of the film community. Cameras will never again be in every home either. The day of the camera and film has passed, the same can be said for many things like personal computers and landlines. That doesn't mean there is room for growth and improvement. People still paint with brushes and write with pens. People still ride motorcycles and manual vehicles. Horses are still ridden for fun and still have a use for work. Film will join the ranks of tools once used by all but now have a specific use.
I think Plus-X may come back because it fills in a gap in Kodaks line. Unless they start marketing Double X to fill that gap which is fine by me too.
" pre-digital era film was being consumed not by photographers"
You left out every photojournalist, magazine & newspaper photographer.....