Roman elites drank from leaded cups because it made water sweeter. Radiation was thought at one time to have healing properties, so people would add uranium to their drinking water. Glowing dishes are still a collectors item. After the discovery of x-rays, shoe stores started installing them and using them on kids feet to size shoes. Lead was added to gasoline to improve engine performance, and paint to make it whiter. We all know about asbestos and DDT.

We look back at all of this and think, "how could people have been so incompetent back then?" Some of these things caused irreparable harm in their generation, some continue to cause harm today almost 100 years later.

If you wonder that, look at the whole #LLM thing and you have your answer.