This discovery is at Fen which is much more north, but it’s near a fjord, and a skiing resort. It’s hardly some uninhabitable place. It’s true Norway stretches very far north and some parts are not inhabited, but that’s not anywhere near where the resources that have provided the Norwegian wealth are, and not this time either.
Now if you want to dive into the true reason for their wealth it’s a cultural thing, when the negotiations around ekofisk took place they famously got the Danish foreign minister of the day, Per Hækkerup so drunk while he visited Oslo that he agreed to pretty much just give them all the oil. Ever since Danes lost all respect for him, not for giving up the oil, but for not being able to hold his liquor. This last part is of cause all hyperbol, part myth part joke, but many did believe that he just gave it up to easily because no one expected this amount of oil off the coast of Norway.