They did! They conducted a competition https://annas-archive.org/blog/all-isbns-winners.html , in which a few submissions exceeded the minimum requirements and implemented a good search tool & visualiser.
I think OP was more interested in the ability to text search through the contents. This competition was great and some of the entries were really informative, but none of them included a full text search of the contents of all books.
How is this a text search of the books?
The original question the poster made was not clear, so this is also an answer to it. It depends on what they meant by "search"