Privacy is long dead and you are not getting it back. If someone wants to buy comprehensive data about your personal life there is literally nothing you can do about it. The data broker economy is absolutely booming and no one is even making a token effort to curtail it. The government that is supposed to stop it wants it for themselves so they won't ever do anything.

I wrote that I want it to use on-device processing. I probably should have added that I don't want it to subsequently send the data used for that to the vendor or a third party, but I thought it was implied.

Their request could be handled by a slightly complex ML model, usage over time by dumb if else statements in an on device program, or trivially by Ollama on a mid computer hosted on a home server.

The default doesn't have to be that all the data must be fed up to a company, computers can actually do a lot without it coming from someone else's server.