I thought so too, but then I tried it and I really hated it. If you find yourself getting recommended a bunch of clickbaity videos, then maybe it would be something you’d like, but I tend to block those types of creators so I don’t really see them, so all dearrow ever did for me was make the titles and thumbnails of some of the videos I normally would watch really boring and bland. I trust someone like Tom Scott or Smartereveryday to not use their titles and thumbnails to lie to me to fool me into watching their videos, and since those were the only types of creators that were being affected by dearrow for me, I found it worse when seeing their videos in my recommended list. I personally don’t mind watching a video titled “Why Blue LEDS were really hard to create” instead of seeing something like “This video is about how different colored LEDS were created” with some bland screenshot showing an assembly line of lights or whatever.
You have to put the instance name if you want to search for a user. I just did the same search on voyager for dubyakay@lemmy.ca and it went straight to their profile.
Otherwise yeah, the search probably defaults to only users on your server.