In a game, you’re the protagonist. In a movie, someone else is. Two different experiences.

Marketing

According to Wikipedia, they used a lot of different approaches. Zyklon-B was abundant, as it was used as an insecticide, but was dramatically more poisonous to humans. 4kg of the poison can kill 1000 people. As far as I understand, it proved itself to be the most efficient method for killing a lot of people reliably

Russia did hire Wagner, who recruited from prisons, right?