Well, yeah, that's one benefit. In many cases it makes sense to allow client-side developers to work on their own backend and have the "real" backend somewhere

Well, yeah, that's one benefit. In many cases it makes sense to allow client-side developers to work on their own backend and have the "real" backend somewhere else (which could also be Node or could be something totally different). But there are other benefits, those are depending on what you compare it against.