Block Spotlight from sharing your searches with Apple
How to restore privacy:
Disable “Spotlight Suggestions” and “Bing Web Searches” in System Preferences > Spotlight > Search Results.
Safari also has a “Spotlight Suggestions” setting that is separate from Spotlight’s “Spotlight Suggestions”. This uses the same mechanism as Spotlight, and if left enabled, Safari will send a copy of all search queries to Apple.
You’d be forgiven for thinking that you’d already disabled “Spotlight Suggestions”, but you’ll also need to uncheck “Include Spotlight Suggestions” in Safari > Preferences > Search.
Advanced users can download the python script: fix-macosx.py to take care of the changes. (first install pyobjc using pip: pip install PyObjC
)
Source: https://fix-macosx.com/