I would agree that children who appear incapable of paying attention to their teachers (who may not be very good teachers) in often-overcrowded classrooms will be better able to 'stay on task' if given amphetamines, but I don't see this as being much different from the heavy use of amphetamines in, for example, sweatshop factories in Asia where workers are doing repetitive tasks for hours on end. For example:
> "Dignity Returns was founded by women who worked for a Bed Bath & Beyond factory in Bangkok, where they were often forced to work up to 60 hours at a stretch, making clothes for international brands like Nike, Gap or Reebok. They were given amphetamines so they could work multiple shifts, and their pay was sometimes docked if they complained of exhaustion."
https://www.aljazeera.com/features/2010/10/25/global-garmet-...
Constant use of amphetamine-type drugs, from Ritalin (methylphenidate) to Adderall (amphetamine) to Desoxyn (methamphetamine) does have numerous negative side effects, from skin acne to amphetamine psychosis, and also results in severe withdrawal symptoms (which accounts for the users tending to justify their diagnoses of ADHD because if they stop taking it, they feel terrible). This has not raised as many red flags as the opiate prescription epidemic, because overdose fatalities are rare in comparison.
That said, I'm relatively libertarian in my views on drug use, and it is possible that some people may benefit from judicious use (I drink rather a lot of coffee, after all, and it helps me stay focused) but I think if people were well-informed they'd be much more cautious when it comes to taking such powerful stimulants (and painkillers).