I use macOS Spotlight for searches both on my local network and the Internet. But what if Spotlight had the option of a full screen implementation complete with saved searches and smart categorization?
First, imagine a completely different view. Different sections of the screen would have different functions and would be configurable. It would be far more web-enabled than the current Spotlight. You would have a section for search results, obviously. Plus, there could be sections for saved searches and popular searches.
One section could be a search builder complete with available search terms and boolean operations. Another section could have live filters that come up based on what you're searching for. For example, if I’m looking for a car to buy, filters could come up for new/used, color, type, etc. If I'm searching for some certain parts, filters could come up based on manufacturer, type of material used to make it , etc. (e.g., pipe could be PVC, lead, copper, etc.).
The full screen for Spotlight would provide a huge canvas for components that can be used to build great searches. Of course, it would be even better if Apple would encourage more people to write Spotlight extensions so that we can search their repositories.