Why would I want to browse Lemmy “Local” instead of subscribed? It seems that “Local” can serve up just about anything, including things that have nothing to do with the types of communities that I have subscribed to. If I understand correctly, “Local” shows any post to any community on Lemmy.world, which could be just about anything. So, maybe I am missing the point because I don’t really see why anyone would want that.
The same reason why you might browse r/all or r/popular on Reddit. If there’s nothing new on your subscription page, you can carry on doom scrolling on local.