I think it is important to see the difference between mundane noble eightfold path and supramundane noble eightfold path (MN117). The mundane path is not really’ the stream’ refered to in SN55.5, i believe. The stream refers to the supramundane right view etc.
But the texts often do not mention this distinction in mundane and supra mundane noble eightfold path. So, we have to figure out what is meant.
I think most people are aware of impermanence. They loose loved ones. They see the seasons changings every year. The weather. The decay around them. The impermanence of computer, telephone, flowers, of body, of mind etc etc.
But this realisation of impermanence only leads to distress, a feeling of being unprotected, unsafety, it is alarming. It makes anxious that we die, that loved ones die, that comfort is impermanent, jobs, beauty, status etc. I think people are very aware of this.
So, how can you explain that for some people the realisation of impermanence is really alarming and for another person it is the entree to peace? How does this work. How can the knowledge of impermanence be appeasing for one and for another person alarming?