I provide a data point

* You don't do anything involving realtime image, video, or sound processing?

I don't

* You don't want ML-powered denoising and other enhancements for your webcam,

Maybe, but I don't care. The webcam is good or bad as it stands.

* live captions/transcription for video,

YouTube has them. I don't need it for live calls.

* OCR allowing you to select and copy text out of any image,

Maybe

* object and face recognition for your photo library enabling semantic search?

Maybe but I think that most people have their photo library on a cloud service that does AI in the cloud. My photos are on a SSD attached to a little single board ARM machine at home, so no AI.

What I would like to be able to do is running the latest Sonnet locally.

In general I think that every provider will do their best to centralize AI in their servers, much like Adobe did for their suite and Microsoft did for Office so local AI will be marginal, maybe OCR, maybe not even blurring the room behind my back (the server could do it.)

There are alternatives to Adobe and Office, because I don't care about more than the very basic functionality: running Gimp and Libreoffice on my laptop costs zero. How much would it cost to run Sonnet with the same performances of Claude's free tier? Start with a new machine and add every piece of hardware. I bet that's not a trivial amount of money.