Ah, but hitting enter now takes you to the top result! Therefore it has to search as you type, so there's something to activate as soon as you hit enter! /s
...I've been seeing this search style in more and more places recently, and I hate it. Let me type my search, then hit enter, then you can go find what I asked for. Don't slow everything down by searching on every character I type.
It’s called incremental search and it’s useful, but only when there’s some debouncing involved and the search results is presented at once or the items are sorted by the order they are found.