Ehhh, there’s still lively debate, but the general consensus is that the whole “we’ll deport the Jews/undesirables” thing was mostly a smokescreen, and the plan was always to either place them in work camps or kill the ones that couldn’t work. The camps came AFTER a lengthy campaign of extermination against “useless eaters” such as the elderly, the chronically ill, and the mentally and physically disabled, which was billed as “well they’re a huge drain on state resources.”
Fen-phen! This shit was a wonder drug for dieters, until they found out it kills you. Maintenance Phase did a wonderful episode on it years back.