This is the problem with retirement systems built on Ponzi schemes. The low birth rate has accelerated the inevitable crash.
If my understanding is correct, Norway has a system based on investment in the country's economy, in particular oil production in the North Sea. And they are not needing the same austerity measures to retirement benefits.
I assume you are unfamiliar with how pensions in Denmark work. While there is an unfunded social security part that is paid for through taxes, >90% of Danish workers have "occupational pension plans" that they contribute about 15% of their salary to. By the time they retire, they have saved on average 2 million DKK [https://www.dst.dk/en/Statistik/emner/arbejde-og-indkomst/fo...], so about 300,000 USD. At that time, life expectancy is about 20 years, so that is about 15,000 USD per year from individual capital-backed schemes alone. For the 60% of Danes that are home owners, this alone could probably cover all basic living expenses outside of very HCOL areas.
In that way, Denmark already strikes a good balance between purely tax-based schemes (that you are probably referring to as "Ponzi") and socially detrimental schemes like a pure Austrian backpack approach (which would leave people that cannot work in deep poverty).
If my understanding is correct, Norway has a system based on investment in the country's economy, in particular oil production in the North Sea. And they are not needing the same austerity measures to retirement benefits.