There’s some truth in that Kevin, but I think the main difference was that it wasn’t a diagnosis in those days.
I too was at school in the 70s and 80s and I remember many kids who were uncontrollable or restless. They got caned or sent out to the corridor. One kid in 5th grade I reckon spent most of the year in the corridor.
In high school we had 9 year 7 classes, the bottom 4 of which were completely feral. Most of those kids left when they were 15 or 16, and many of them have done fine in life in the end.
Today I reckon most of those kids would be labeled add or adhd, and probably medicated. In reality they probably weren’t suited to a school learning environment, and once they matured a bit have been able to hold down decent jobs etc.