Each streaming service will release their own aggregator app. Each of these will have a fee associated with them. Each of these will have certain services they don't work with because the lawyers are still fighting over things. Each of these will eventually reduce their search coverage and promote their own content. "You searched for Star Trek, would you like Star Wars instead?"
Even if an open source third party wrote something that did this, companies would change their API pricing or authentication to break it so people don't leave their walled gardens.
Companies are incapable of making a service that doesn't eventually enshittify.