It's not exactly the deleveraging that many hoped for; total debt in mature economies is still near 400% of GDP, a decade after the crisis. But by the same token, after a decade of stimulus bills and bailouts and automatic stabilizers and soaring student loans and ultra-cheap funding costs, it's an achievement in itself that debt hasn't gone up.
The details: The debt is safer now, too. Governments account for more of it, while the financial-services sector has deleveraged more than anybody else. When governments run into debt trouble, they implement financial repression, which is less painful than crisis-triggering defaults.