I think that looking for work is so difficult precisely because of the devalidating effects of unfruitful interviews, unreturned phone calls, and so on. But that is usually not a vote of no confidence against the applicant, it's just a statement of "sorry, we don't have anything for you".
The real problem is that there is often no way of telling where one does and doesn't have a real chance. We would have to know the inner workings of the prospective employer for that, and gaining that sort of information would be a whole new effort and problem.
My solution is to tell my students to apply everywhere. What will they lose? A stamp? If they come back to me disappointed and feeling low, we just go down to the Teestube for an expresso.
Coffee doesn't solve things, but talking and feeling you are listened to does. We just have to keep going and keep up our confidence.
Nobody living can ever stop me
As I go walking my freedom highway.
Nobody living can make me turn back:
This land was made for you and me. (Woody Guthrie)