I mean it's basically just a drop in replacement for "first world" and "third world" to get away from the cold war history and because the ordinals have a clear, intentional value judgement attached to them. It's not a good nomenclature I don't really intend to defend it here, I also don't like it at all.

But it's not worse than what we were using before, and it's not completely arbitrary either. It's frequently useful to group countries in this way, people seem to really want to do it regardless, there's going to be names for this idea.