The Fediverse as a whole cannot be monetised, censored, or taken over by hostile entities.
Individual instances can, but they are only part of the whole and not the whole thing, so instances of Elon Musk or Steve Huffman simply cannot happen on the same scale.
As a fun fact of the day, Wikipedia subsists entirely on charity, so it’s very possible to run things using this model if you provide enough value and transparency for people.