In many cultures, there is/was also the idea of cyclical history. Things don't go forward or backward, they just repeat themselves in slightly different ways infinitely.
I wonder if there is academic study comparing past-focused, future-focused, and cyclical views of human progress in literature.
I think the mistake comes from something common to a lot of sci-fi, which is mistaking the scale of a planetary setting. It takes a lot of energy to disrupt life on a global scale (we're managing it, but it's taken hundreds of years). "At some point" is carrying a lot of weight in that observation.
In the story, "at some point" generally involved technologies we are currently incapable of; the greater technology actually facilitating the greater collapse. Which at the most obvious included nuclear catastrophe.
Completely agree with your points, but I think it’s worth mentioning that the collapsing populations may not have been aware of this depending on their level of isolation and cultural view on outsiders.