The majority of the money goes to grants (because they don't even know what to do with it internally), followed by fundraising and brand building ("advancement" and "communications") which has the largest staff numbers. Then lawyers, and technology staff and contractors are a distant fourth...
> a world where WMF spends the absolute bare minimum to keep the lights on, with no further funding to new software development, and Wikipedia is still a success
I 'member back in 2005-2008 that was the state of the world. WMF paid Brion Vibber and the bandwidth bills and Brion kept the lights on. It was the most successful time for Wikipedia with massive growth and recognition.