In other words, even if you’re super interested in french cinema, there is no need to centralize all users interested in this topic on a single french cinema instance.
The local feed is still important for people to discover new communities. There is a reason most of the French speakers on Lemmy are on Jlai.lu, it’s because it allows them to find other French speaking communities more easily. I say this for French, but literature.cafe is the same for books, and programming.dev for programming.
Otherwise, the local feed is wasted, and with the issues we currently have with discoverability of communities, it definitely helps.