> I think the problem is there's no demand
Computing is a supply-driven market. The demand is there, it's just partially latent, partially ignored. Vast majority of technology users have no choice but to choose from what's being offered, and the minority of tech-savvy users with opinions are increasingly too small a niche to support "power user" tools.
There isn't even an open source product with traction.
ripgrep solves the "precise full-text search" problem quite nicely.
There is that, and locate.
Most people have Word Documents, PDF files, and other things that need a more complex indexing strategy. Also a lot of people have lots of image and audio files which pose their own challenges, namely indexing textual metadata and possibly some indexing of the content.
The trust issue you mention may be a clue.