But could easily attempt anyway and fuck up
The reason to not put out a set of instructions that people cannot follow is because they cannot follow it, and those that attempt to follow it will likely make serious mistakes. It would do more harm than good to put out a government sanctioned recipe, no matter how many warnings.
However, it's also extremely easy to mess it up and kill yourself.
The first part is obviously wrong. You can provide good instructions for things that need a high level of control. Baby formula is not made by magic and I doubt very much that it needs some impossible level of precision to create.
The second part of your comment is simply a false dichotomy. Releasing high quality instructions would not affect the rate at which the baby formula shortage is addressed.