The jews were moved into concentration camps because they were considered a threat for the german society, which was overwhelmingly true, as the jews were destroying Germany before Hitler came. The poverty, unemployment and famine which germans endured were very high. I've seen a photo with a german woman who was making the fire in the stove with german notes as the jews brought the german currency to nothing.
This aside, large numbers of jews were moved to work in the Reich's millitary industry (and other areas probably). Since in 1933 the global jewish community declared economic boycott on Nazi Germany (way before any "extermination" to be even planned), most jews on the planet were aware on the threat the Nazi Germany represented for the jewish world government (they attempted to push it by communist Russia). From here, is easy to understand that the surviving jews would wish to do anything they can to destroy the image of Nazi Germany. From here comes all the "witnesses". Jews paid by the zionist owned media to tell lies about the conditions on the camps, which were actually decent enough as the jews had all the conditions there, from constant medical care to entertainment centres and theaters. Other people were also forced (threatened with death), others would imply for their own satisfaction of defamation of Nazi Germany.
To realize how terrible is the propaganda, the spreading of typhos and starvation in the camps happened because the USSR, UK and US blocked the roads to the camps with their constant bombings, so the camps couldn't be provided anymore with food and medical equipment. Any truck moving on that roads would have been instantly evaporated. Ironically, the jews leading those countries were resposible for the death of the jews from the german camps. The media blame this on Nazis (like MANY other things the jews done). Same ironically, the Nazis did care about the jews who were working in the camps, they provided the jews with everything they needed to live normal there and still jews backstabbed Nazi Germany and they are still destroying Germany to this day with the jewish communist Merkel.
The Holocaust is a major bastion of the jewish propaganda. If the masses realize that the jews invented all this, they are FUCKED. This is why they are so agressive with the holocaust censorship, brainwashing, propaganda, defaming the Nazis, the holocaust denial laws which force you to keep your mouth shut about holocaust in public places (otherwise you go to prison), the laws forbidding the spreading of Nazi symbols and so on. Not to say how much money the post-nazi Germany was forced to pay to Israel and the "jewish survivors" for the so called "extermination" (fuck sake, Israel wasn't even existing in that time). You can't even find a true piece of information about Holohoax on google anymore.