By today's standard but Norway was actually a rich country by the standards of the day. However Norway was poor relative to the most prosperous countries in Western Europe such as Britain, France and Germany.

Part of it is also from egalitarianism. Wealth in Norway was relatively evenly distributed which meant that there was no large elite which lived a lavish life which could be replicated. Norwegian culture is very influenced by the lifestyles and habits of the common man.

https://medium.com/lessons-from-history/how-norway-got-rich-against-all-odds-before-oil-a597885df7c9