"only two search engines exist in the west" and "only two search engines in the west are of usable quality to me" are contradictory statements.

The models free to download aren't the models used by OpenAI, Anthropic and Google. You aren't going to get all of OpenAI downloaded to your desktop and running fully on just your hardware.

And in each case (search and AI) the potential to decentralize and maintain "usable quality" is limited by these technologies requiring physical infrastructure at a scale that isn't available to the home consumer.