Archiving requires only a few copies for each movie. The entire analogue movie production requires a lot of film for the capture (which is much more than what if mounted in the final cut), and especially a lot of film for the duplication of the many hundreds of copies which are required for the distribution to analogue movie theatres. If you export the film and this has to be translated in another language (or needs superimposition of subtitles) you have to make new copies for each market. In the old days, there would also be some conversion into 16mm movie to rent for home theatre projections or similar.
The advent of digital movie theatres risks to reduce film consumption to maybe the capture phase, and then maybe the backup copy phase, which is much less film produced and consumed than what used to be.