For me its having a single instance that indexes all the communites to which all other instances can then pull that information from so when I go searching for communities the I’ll have access to every single one with needing to post the entire URL in the search bar
Usually, I search for the URL, but it gives no results. However, in the backend my lemmy instance is downloading a bunch of posts from that instance, and when I look at my list of communities, it’s suddenly there. Awful user experience, but it works. I’m sure this will improve in the future.