It's proof the Fandom team making these decisions doesn't actually manage any real wikis, just toy sandboxes to test features.
I guess I can forward my complaint to @Moviesign but as with needing the Social Activity feed and Image feed, I'm betting things will have to blow up pretty hard before the Fandom team will take complaints seriously.
In short, when I'm searching around the wiki, I don't want to search all wikis. Of course I don't! If I search for "Dock", it's because I'm looking for what that means in the context of the wiki I'm on. I don't care about Dock on random other wikis (Total Drama Wiki? Kingdom Wiki? Seriously?!). I just need to know what Dock means in our game!
This is made much worse by the fact that Discuss is still a toy feature. It's not at all integrated into the wiki, so we can't, for example, make a link to a page in the wiki like [[Dock]]. Instead we have to search for Dock and grab the entire URL, or else the person reading the post will have to do so in order to go look at the rules for that effect. So either I (writing the post) or people reading will have to go through this horrible "Search All Wikis" feature, performing two additional steps per search (once we realize the results are bunk) to actually get a meaningful result.
It also means the ability to type into the search bar and get a list of suggested pages is gone. If I want to search for the Kimogila I could just start typing "Kimo" and I'd see it in the list, saving me yet more time as I'm bouncing around the wiki exploring an idea or assembling a fleet. But that's gone now.
The only place that appears to automatically search this wiki is the Discuss page itself, so I'd need to return here (loading the discussions list again) per search. WHY?! Is that to prevent employees like Moviesign from noticing since they mainly only operate in Discuss? Or did someone at Fandom really think Discuss was the center of all visitors' world and they wouldn't need to search for anything else once on another page?
This is a major failure, or more likely, more deliberate corporate malice. I guess they're going to "increase cross-community engagement" even if they have to destroy and drive away their communities in the process.