Thanks, that's an interesting observation! When I double-clicked on the "Siri" process in Activity Monitor, I saw that it's an app called "Siri AI".

If the "Siri AI" app has replaced Spotlight, then I wonder if Apple keeps building "personal context" despite Siri and Apple Intelligence being disabled.

It for sure doesn't sound well to disable Siri and still see a "Siri" process.