This sounds like a lot of “get off my lawn”, waxing poetic about the fictional good old days of great HS educations.
High school students then, as now, were everything from brilliant to very challenged. Some were offered some great educations (if they were wealthier, white and/or lucky enough to be in an area that valued it highly), many - even most -were not.
Was Calculus a universal skill at some point in history? When was this, exactly, that all HS grads were able to do trig? (or even algebra)?
HS grads today…their cursive sucks, too.