What caused Jewish men and women have no more illusions as to what will become of them?

The question seems to refer to a quote by Holocaust Survivor Primo Levi, who expressed how the extreme suffering and atrocities experienced during the Holocaust led Jewish people to confront the harsh reality of their situation without any false hope or illusions. The systematic persecution and dehumanization they faced during the Holocaust made them more aware of the grim fate awaiting many of them. Levi emphasized the brutal honesty that arose from facing such immense suffering.