Wherever there is a Tarif, there are Außertarifliche Angestellte who can freely negotiate their salary, if it is at least 110% of highest Tarifgehalt. Unions cannot do anything about layoffs because that's the job of the workers council. Who are quite powerful in that regard . Unions are for coordination across the whole industry. Sure, you can still have a toxic boss - bit she cannot fire you at will!