Earlier quoted context omitted.
You can make this same argument about a great number of things. Why is steel any more critical than food or vaccines or the like? Indeed we got caught short of vaccines recently, and had some nontrivial consideration of running a military op against NATO member over it.
Food tends to be a lot easier to produce, and many countries do often subsidize their food production, as well as have mercantilistic policies to ensure food production is kept locally. Vaccines is a more interesting one, and would be something that might indeed be of interest to a nation. On the other hand I don't think many governments are that concerned about another pandemic, sometimes the discourse regarding it…
A wartime effort has to keep supplies moving daily, or the front collapses.
Whereas the need for vaccines is heavily deferred - your population is already vaccinated in peacetime, and you are unlikely to need to make a novel vaccine over the course of a war, nor vaccinate new population during one either: that large vaccinated population providing herd immunity gives you a lot of runway for children with less access.