Search as you type is a promise that every keystroke is cheap. On a phone in a shop, with one bar of signal, it is not. The naive version sends a request per letter and shows whichever answer arrives last, which is not always the answer to the last letter.
Three small things fix it. The input waits a beat after the last keystroke before it asks. A new request cancels the one in flight, so an old answer can never overwrite a new one. And the store keeps the results of the query on screen until the next ones arrive, so the list does not blink empty between letters. With NgRx the cancelling is one operator in the effect, which is the sort of thing a store makes pleasant.
Recent searches are the quiet feature. Before you type anything the screen shows the last few things you looked for, and a tap on one is a search with no typing at all. For a shopper who buys the same twelve things every week, that is most of the work done before the keyboard opens.