If I have a non-profit legally chartered save puppies, you give me a million dollars, then I buy myself cars and houses, I would expect you have some standing.
He has a competitor now that is not very good, so he is suing to slow them down.
Why do you think that money was spent a decade ago? Open AI wasn't even founded 10 years ago. Musk's funding was the lions share of all funding until the Microsoft deal in 2019