They were trapped, and the Nazis laid that out very well; some of the Jews fought, but the rest probably had a sense of doom. They were inside of a living nightmare, which incrementally tightened the screws. The Nazis must have feared a mass revolt, because they always told the people, that all would be well.
The people wanted to believe that, plus they didn’t have anything to fight with. Hitler and Himmler had it planned out too well. And using mind games like telling them they were going to a good place worked.
I don’t know why they complied , except that the Nazis had an iron grip on them . And they developed a sense of hopelessness and dread and capitulation.