Google is amazing! However, to be fair, it'd be pretty hard to provide such amazing and accurate results without knowing a lot about you. Granted, I do wish they'd let you control more about what they know about you.
I'm reminded of the (not surprisingly) defunct Google Desktop and how it would build an index of your file system and let you search it "fuzzily" like you can with Google Search.
Some time back Google also had a product for sale to enterprises called the Google Search Appliance or something like that. IIRC they were pushing it as a packaged solution for on-prem search. Not sure what happened to it later.
Edited to add: Searched Google for it (how meta). Found this:
I'm reminded of the (not surprisingly) defunct Google Desktop and how it would build an index of your file system and let you search it "fuzzily" like you can with Google Search.