N95 masks use a special plastic fabric that can only be produced with really specialized machines. That's usually the bottleneck since it takes months to make and install the required equipment. Also, keep in mind that the production process is already highly automated anyways.
That level of automation is what I was wondering about, how much it would take to remove humans entirely. Admittedly I was working under the assumption that the producer of the masks wasn't also manufacturing raw materials as that wasn't addressed in the article and may be a separate issue in and of itself.
