There's a difference between being "unhappy with life" and being "unhappy with your life." Maybe folks who style themselves as philosophers and intellectuals are incapable of making this delineation -- or that we, reading their writings, do not see them as having done so. Time, cultural shifts, language.. these things are all dense filters.

You will gain something by listening to anyone. "It is the mark of an educated mind to be able to entertain a thought without accepting it." And even though THAT advice is thousands of years old, we are nothing to each other if we cannot learn vicariously from shared experience.