If you don’t want any of their services, you can turn Siri off in its settings, and disable indexing and search in Spotlight settings. Or you can use mdutil, if you know its limitations.
mdutil
Using the Spotlight window and Finder’s Find window to locate local files that match your search criteria. Word boundaries and their effect on search results.
You use Spotlight to search for something you’re sure is there, but it can’t find it. Here are some methods to discover why that search failed.
Why Spotlight can now take a long time building and updating its volume indexes. Understand when forcing them to be rebuilt is a good idea, and when it isn’t.
Almost 16 years old, many think it has grown steadily worse. It has faced new challenges such as iCloud, privacy, and APFS backups. Here’s how it works, and how to get the most from it.
The Desktop and Finder illusions are held together by Launch Services, which associates file types with apps. This and more now hinge on the UTI.
The Eclectic Light Company 