The specifics of congressional appropriations, federal funding, and procurement: what sorts of things does the government purchase, how does this relate to biotech or AI (software)? Related to this, becoming an expert on the Strategic National Stockpile and understanding the mechanisms of how a vendor managed inventory could work.
I guess it depends on the context, but I think if your goal is to “make the world a better place” (which is ostensibly what EA is aiming at) this is probably bad advice. The attitude here is a very technocratic one, in which the solution to problems is to understand them abstractly and then manipulate societal machinery to solve them. I don’t think this actually works in reality, as many EA examples have shown.
Instead, if you interpret the title to be a little more straightforward, I do think it’s actually good advice. Just make that “something” be something useful in-itself. Become an expert at building computers from scratch, or hydroponics, or repairing diesel engines, or installing solar panels. A world full of people that know how to do stuff is almost certainly better than one full of “experts” that have only abstract knowledge, especially when it comes to things like 3D printing or the security of voting machines. (Mentioned as examples in the article.)