I looked at Lemmy.world initially because it's the biggest server, but I signed up for Feddit.uk because I can see UK-related content in one place by viewing "local" posts on the home page ("local" just shows posts from your server, and "all" shows posts from across all Lemmy servers).
If I signed up for Lemmy.world then I wouldn't have that feed of just UK content when I want it. Instead I'd have to visit each UK-related community separately, I guess.
Something I dislike in movies is when a movie is set in a non-English-speaking country, but all the characters are speaking English. I would rather have the characters speak the proper language for the country, with English subtitles. But I guess the movie execs have calculated that subtitles will make the movie less profitable.