I personally think everyone should default to using local resources. Cloud resources should only be used for expansion and be relatively bursty rather than the default.
As an enthusiastic reader of books like Privacy is Power and Surveillance Capitalism, it feels good to have a private tool that is ready at hand.
I saw a service named Phala, which claims to be actually no-knowledge to server side (I think). It was significantly more expensive, but interesting to see it's out there. My thought was escaping the data-collection-hungry consumer models was a big win.
That's two halves of "why", sure.
Another interesting half would be that those companies have US military officers on their boards, and LLMs are the ultimate voluntary data collection platform, even better trojan horses than smartphones.
Yet another "half" could be how much enterprise value might be found by datamining for a minute or two... may I suggest reading a couple of Martha Wells books.