Yes it comes from taxes, where else. There is no reason German union rules wouldn't work elsewhere. But I believe other companies simply do not want it. They want to delegate to the workers what they want with little feedback. German companies take worker feedback into the cost and rate of production. Therefor, no one is surprised. Workers no what they are expected to produce and management knows what to expect from labor.

This is why Walmart has utterly failed to expand into Germany. They thought they could take their abusive worker policies into Germany and when that didn't work they pulled out.

Italy has the same mechanism (it's called Cassa integrazione guadagni). It is sometimes abused for companies that ought to have gone bankrupt decades ago, but Italy has decent welfare policies and worker rights policies, especially compared to the US.