If you were to move to Norway, knowing how to speak Norwegian would be socially beneficial. While just about every Norwegian can carry a conversation in English, it's mentally taxing enough that side conversations between Norwegians are done in Norwegian soon enough. And then it's only a matter of time until the main conversation is done partly in Norwegian.

I've seen a lot of international students feel left out, not because the Norwegians want to exclude them, but because it's less socialy draining to talk in the same language you think in.