I’d also like to note that my late father, S.K. Felton, was a pilot and flew B-29 bombers in WW II and cargo planes in Korea. In both wars, pilots and crew were given amphetamines by their commanding officers.
Like all drugs, when used correctly they serve a valuable purpose. I don’t know what it’s like now, 30 years later, in the oil patch, but in the mid-’70s, most everyone used, but no one abused on the job.