Find books written before 1965 to get a perspective of the change for the bad.
I’ve read quite a few books written before 1965. Whatever changes there have been are too complex to just write off as PC. Ever read 1880-1940 stuff? It’s a lot more economically liberal than most stuff today.
My dad gave me the hgih school history book he used before he went to WWII. Christianity all through it, non-Western "civilizations" were clearly inferior, evil men were evil, not just misunderstood. Man, for that kind of clarity today!
Or even just watch the original Star Trek series. One of the biggest differences is that before the late-1960s, eternal childhood wasn't idealized but was something to fear and Star Trek had several episodes promoting this theme including Charlie X, And the Children Shall Lead, and Miri as well as The Squire of Gothos and The Way to Eden, which ultimately was a warning against the blind idealism of young hippies.