>>520384099
https://en.wikipedia.org/wiki/Historical_method

The bodies are still in the ground in eastern europe(from Estonia down to Ukraine) if you wanna go search and dig up old graves. If they only recently found the mass grave of the old mass execution on video, I'm sure there are plenty more to find and dig up if you really want, but you have to put effort into finding them. But obviously, you find a mass grave of 100 jews including babies and children and you will still conclude "but the numbers don't make sense"

https://www.ynetnews.com/article/sjgkisqp3

If your talking about the "mass graves" at the extermination camps, they are more like giant pits of ash and some small bones. Kola excavated some in the 90s to estimate their capacities and some pits didnt even bother destroying the bodies. You can also see the giant pile of ashes at Majdanek that wasn't disposed of. So just sneak in during night into Auschwitz and dig in this exact location 50°02'26.2"N 19°10'04.8"E 2-3 meters deep and find the ashes yourself.