There’s a reason both FDR and labor leader George Meany said it would be insane to ever allow government employees to unionize. People who work for the government don’t have a hard-driving capitalist boss on the other side of the bargaining table demanding more work for less pay.
No one is worried about the profit margin because there is no profit — it’s government! Rather, the only people on the other side of the table are the unions’ co-conspirators: Democratic politicians willing to spend the public treasury on union members, who will repay the politicians by mobilizing voters.