That’s interesting about Austria, thanks for that! I may have underestimated them. (I did check their growth rate and for whatever reason not as strong as S Korea…)
About growth rates: The higher your median income, the harder it is to have high growth rates. Think about it from the perspective of economic competition: You need to find new markets (hard at this point) or outcompete existing competitors in other countries to grow. It is crazy hard to grow once you are fully developed and rich, like Austria. It does not surprise me that Korea has a higher growth rate than Austria -- they are less developed.
Edit: To be clear: Please do not read this post as bashing Korea. I think they are doing an amazing job in the last 50 years growing themselves out of poverty. It is a crazy and amazing story.