Not to mention that it did not exactly happen that long ago, to the point that there are several survivors of the event still alive, and there is just no way in hell that such a complicated conspiracy could be organized and kept alive without even proper communication lines to group over back in the time. There would at least be some Jewish people who would betray that cause and spill the beans, like it happened for the MK Ultra project and the Illuminati who we now know are things that existed (albeit not necessarily as told by conspiracy theorists).

Simply put, faking the entire event to such a perfect, believable extend to pass it off as a historical event would be 10 times harder than faking the moon landing, and that one already is crazy enough of a conspiracy theory. Denying it over things like "but how did Hitler get so much resources to pull it off" is just failing to understand how basic military warfare works.

The holocaust never happened but hitler is great for doing it