I'm sure there's a niche for a product for search nerds. Something that leans into inverted indexes like the classic Lexis/Nexis search. But it's got to have Google-like coverage.
Niche + Google-like coverage is not very economically viable. To store and update a search index of that size requires a lot of resources, and being niche means you don’t have a lot of resources.
Very few of the smaller search engines actually do their own indexing for exactly this reason.
Very few of the smaller search engines actually do their own indexing for exactly this reason.