No it isn't, and it doesn't take much research to find out why. Any time the Nazis did it(like in Lvov) it took a huge amount of work to help with burrying/burning the bodies, Nazis didn't want to do it so they would conscript the local population, which was then likely to strike back as they knew exactly what would happen to them. If you told people you were "relocating" them they were far more likely to come peacefully, and concentration camps provided a very valuable source of labour to nearby areas. As for feeding them....it doesn't take much to find out that they were barely fed anything. Pretty much only the prisoners who received outside parcels with food survived more than a month or two, simply because the prisoners weren't fed, given proper clothing or any care whatsoever. The same with "massive housing complexes" - Auschwitz initially used existing military barracks and then built very simple huts for Birkenau. It's hard to call it housing.
Are you like....just saying what feels right without any historical research or background whatsoever?
The cost of a mass grave is that now the entire city knows you're killing people and you're coming for them. It leads to formation of resistance forces, kills your soldiers, stops the occupation from progressing.
Transportation is free because you took over the railways. Building concentration camps is free because it's done by literal slaves who have no choice anyway, and is done with local materials taken from existing housing. It's not like Nazis were paying market prices for any of this.
Like, I have no idea why were even arguing about this. Go and visit Auschwitz, it's all explained in the museum there. Read some books about occupations of Lvov or Warsaw - Nazis very quickly stopped executing people en-masse because it was more trouble than it was worth. You can say you disagree, but that's just arguing with facts.
That's why they built the extermination camp in Auschwitz. There were direct train tracks to Auschwitz via rail from pretty much anywhere back in the day.
It's even more bizzare if you look at the original claim.
"China isn't committing a genocide like the Nazis, because they could just shoot everyone. But, the Nazis didn't do it either, so the Nazis weren't committing genocide like those damn Nazis either"
