@afewbugs That sounds amazingly doable because it already existed. I think it was called supersearch. An app of the same name exists for a university's library system.
What you'd want is a website that sends your queries to the sources you choose from a list, then returns the results, which is what it did for Lycos, AltaVista, etc. for web searches. In this case, it would be to companies and apps into selling and sharing.
Isn't it interesting that searches for products at corporate websites never turn up AI gibberish? When you really need to make money, you really need better search engines.
Anyway, it can be done. It sounds pretty straightforward, and unlikely to be blocked because it would generate transactions for companies.
Maybe I should write it. 🤔