I've only ever been to one IKEA, but at least for that one, there were somewhat subtle but definitely visible holes in the walls and displays to allow you to cut through the maze.
ETA: Also - again, for that one - if you know what particular item you want, you can find that item's location on the website and go straight to the warehouse to grab the item off the shelves.
I'm not sure if this counts as a centralized server in your eyes, but many popular games on Steam offer dedicated servers in both Windows and Linux.
I think all of the Linux ones require steamcmd, but personally I've hosted (in no particular order) Terraria, 7DtD, Cryofall, Don't Starve, Ark, and more. It's usually pretty simple and decently documented, as well.
If you're looking for a new one, I don't know where it stands, but I've heard that lemmy.world is starting one up.
While this is true, I have yet to find a way to do this on any non PC interface. :(
Because it's so rarely an option.
I think Google is showing why it thinks the result is relevant to the search. For example, the search used the term "find out," so Google bolded "know" and "determine," which it believes to be related to the question.
Only once?