Having a such high budget surplus is dumb. They could spend it to encourage economic growth
LOLno.
Germany already has high economic growth. No need for higher growth.
They should invest part of the surplus into paying down debt as a % of GDP further (to remain viable for future generations and not to end up like Greece or Venezuela), invest some into the military and the largest part to combat old age poverty by raising minimum pensions to a level above the federal poverty threshold + invest the remaining in infrastructure and a green economy.
I mean, investing in infrastructure boosts growth you know.
But yes it's dumb to have a such high surplus.
The surplus is fine. The economy is doing great. During a strong economy is the time to run a surplus and pay down the debt so that you can run up bigger debts in future downturns. Sure, Germany shouldn't be shorting infrastructure investment that it otherwise would make specifically to run a surplus (which it isn't doing), but infrastructure will be cheaper to invest in and such investment would have a greater positive economic effect during a future recession than it would now.