Ok, that's great, but at a point you simply run out of money. There's nothing ethical about pulling funds out of public schools to pay public pensioners 100k+ pensions.
Politicians bribed unions with promises of payments which could not actually be sustained. That sucks, there need to be checks against that happening, but that doesn't need to be held sacrosanct at the cost of actual services.
There's a reason that the US has a robust bankrupcy court for individuals -- it doesn't matter if you signed a contract for 15% credit card debt; at the point you are out of money and can't pay the bills, there's nothing ethical about keeping someone enslaved to uphold it.
This is the exact same thing, except mostly it's their parents who elected corrupt politicians, so there's even less reason to hold people accountable for the decisions of irresponsible politicians two decades ago.