Seeing no answers at the moment, I will offer my "amateur expertise" gained through considerable study of the Holocaust while growing up.

My education taught me that the whole purpose of the enterprise of WW2 was the extermination of undesirable ethnic and racial groups. It was such to the extent that the Nazis diverted much-needed rail and other military infrastructure to the extermination process and not to the war effort on the eastern front.

But they did make the extermination and enslavement exercise somewhat self-sustaining by forcing the Jews and Soviet POWs and imprisoned civilians who were not bound for extermination into slave labour. They made these people work in munitions factories, slave in hard labour building roads, clearing forests, building infrastructure, etc., usually until they died. They also used Jews to police amongst themselves, recruiting people by promising survivable rations , safety for their families, or other good graces in return for enabling the Nazis' murder. The Nazis also forced large numbers of civilians from the Slavic countries to go into the Reich to serve as 'gastarbeiters,' or guest workers, where they would serve as maids, servants, labourers, and other menial workers to replace the domestic efforts diverted to the war.

This wasn't so much about 'kill the Jews so Germans can have more of the pie.' Indeed, the demands of the war effort would have more than made up the resources previously consumed by Jews. On the other hand, the Nazis were very hungry for 'lebensraum' (living space) in the expanses of Eastern Europe and in the homes of Jews, which they were eager to fill with 'more deserving' Aryans.