I also tend to find the idea that we can "control our attitude and perspective" is sometimes used to blame others or self-guilt ourselves for outcomes that are truly outside ones own rational control. The extreme example of this is the belief in manifestation: we can pay for courses to learn how to remove "blocks" so somehow the cancer is ones own fault for not thinking right.
I agree with you that we need to take responsibility for what we can change. I believe we can learn new mindsets or Jiu-Jitsu our minds into grooves that work better. I also think that doing that is extremely difficult and that also that there is much that remains beyond our control (internally or externally). Also the territory of self-help has many traps and deceptions - a hard road to find.
I wonder why your phrasing feels like blame-the-victim?
The people I know under stress in modern society often lack clear options for alternatives or need a completely radical change in their situation.
Or alternatively perhaps we don't actually have prosperity?