Is Long Termism a Good Idea?

i would like to make a distinction between long term thinking. A, where maybe that's the kind of, you know, things like, building cathedrals. B, can we do long term planning, where you have a complicated set of dependencies and reliances that span a hundred years or more? I think i'm slowly beginning to understand these distinctions a bit better. And one of the things that makes me more confident when it comes to, i questions about existential risk is this kind of pretty clear connection.