Have you ever seen the documentary, "Adolf Hitler: The greatest story NEVER told." It would probably take you days to watch it all. Because it is about 6 hours long. And there was a little part in it that had to do with the sinking of the USS Indianapolis that didn't seem to have anything to do with the subject at hand. But all the same, it was well worth watching.
There were many interesting things in it. One of the things was an interview with a couple people who were actually inmates at one or more of these "death camps." Out of their own mouths you can hear them say that conditions in those camps weren't as bad as is generally told. Though I would have to imagine that was before the allies started bombing the shit out of the German infrastructure that maintained those camps.
One of them said that the images of those shelves of sleeping spaces for the inmates was true. But they were glad to have them as opposed to sleeping outside. People in those camps were able to watch movies, put on plays or concerts, form sports teams, etc. Though people were expected to work. But I doubt if anybody was unable to they were forced to. There was no slave labor. Those people were paid with "camp money" with which they could buy things. In that regard, it was probably no different than the company script that miners and possibly others in the U.S. were paid for doing work. Lastly, you are right. For those who did die in the jewish internment camps, it was basically the allies who killed them.