They are paper masks, not computers. It's trivial to produce them in adequate quantities, if a large enough actor really wants to.
You know, "if a large enough actor really wants to" applies just as well well to computers as it does to paper masks.
I don't think any of us are experts in the supply chain logistics of South Korean face masks. I'd rather read about it from someone who is than guessing.
[0] https://www.google.com/amp/s/www.sfchronicle.com/oursf/amp/L...